34. Window System Integration (WSI)
This chapter discusses the window system integration (WSI) between the Vulkan API and the various forms of displaying the results of rendering to a user. Since the Vulkan API can be used without displaying results, WSI is provided through the use of optional Vulkan extensions. This chapter provides an overview of WSI. See the appendix for additional details of each WSI extension, including which extensions must be enabled in order to use each of the functions described in this chapter.
34.1. WSI Platform
A platform is an abstraction for a window system, OS, etc. Some examples include MS Windows, Android, and Wayland. The Vulkan API may be integrated in a unique manner for each platform.
The Vulkan API does not define any type of platform object. Platform-specific WSI extensions are defined, each containing platform-specific functions for using WSI. Use of these extensions is guarded by preprocessor symbols as defined in the Window System-Specific Header Control appendix.
In order for an application to be compiled to use WSI with a given platform, it must either:
-
#definethe appropriate preprocessor symbol prior to including thevulkan.hheader file, or -
include
vulkan_core.hand any native platform headers, followed by the appropriate platform-specific header.
The preprocessor symbols and platform-specific headers are defined in the Window System Extensions and Headers table.
Each platform-specific extension is an instance extension.
The application must enable instance extensions with vkCreateInstance
before using them.
34.2. WSI Surface
Native platform surface or window objects are abstracted by surface objects,
which are represented by VkSurfaceKHR handles:
// Provided by VK_KHR_surface
VK_DEFINE_NON_DISPATCHABLE_HANDLE(VkSurfaceKHR)The VK_KHR_surface extension declares the VkSurfaceKHR
object, and provides a function for destroying VkSurfaceKHR objects.
Separate platform-specific extensions each provide a function for creating a
VkSurfaceKHR object for the respective platform.
From the application’s perspective this is an opaque handle, just like the
handles of other Vulkan objects.
|
Note
On certain platforms, the Vulkan loader and ICDs may have conventions that
treat the handle as a pointer to a structure containing the
platform-specific information about the surface.
This will be described in the documentation for the loader-ICD interface,
and in the |
|
editing-note
TODO: Consider replacing the above note editing note with a pointer to the loader specification, when it exists. However, the information is not relevant to users of the API nor does it affect conformance of a Vulkan implementation. |
34.2.1. Android Platform
To create a VkSurfaceKHR object for an Android native window, call:
// Provided by VK_KHR_android_surface
VkResult vkCreateAndroidSurfaceKHR(
VkInstance instance,
const VkAndroidSurfaceCreateInfoKHR* pCreateInfo,
const VkAllocationCallbacks* pAllocator,
VkSurfaceKHR* pSurface);-
instanceis the instance to associate the surface with. -
pCreateInfois a pointer to aVkAndroidSurfaceCreateInfoKHRstructure containing parameters affecting the creation of the surface object. -
pAllocatoris the allocator used for host memory allocated for the surface object when there is no more specific allocator available (see Memory Allocation). -
pSurfaceis a pointer to a VkSurfaceKHR handle in which the created surface object is returned.
During the lifetime of a surface created using a particular ANativeWindow handle any attempts to create another surface for the same ANativeWindow and any attempts to connect to the same ANativeWindow through other platform mechanisms will fail.
|
Note
In particular, only one |
If successful, vkCreateAndroidSurfaceKHR increments the
ANativeWindow’s reference count, and vkDestroySurfaceKHR will
decrement it.
On Android, when a swapchain’s imageExtent does not match the
surface’s currentExtent, the presentable images will be scaled to the
surface’s dimensions during presentation.
minImageExtent is (1,1), and maxImageExtent is the maximum
image size supported by the consumer.
For the system compositor, currentExtent is the window size (i.e. the
consumer’s preferred size).
The VkAndroidSurfaceCreateInfoKHR structure is defined as:
// Provided by VK_KHR_android_surface
typedef struct VkAndroidSurfaceCreateInfoKHR {
VkStructureType sType;
const void* pNext;
VkAndroidSurfaceCreateFlagsKHR flags;
struct ANativeWindow* window;
} VkAndroidSurfaceCreateInfoKHR;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
flagsis reserved for future use. -
windowis a pointer to the ANativeWindow to associate the surface with.
To remove an unnecessary compile time dependency, an incomplete type definition of ANativeWindow is provided in the Vulkan headers:
// Provided by VK_KHR_android_surface
struct ANativeWindow;The actual ANativeWindow type is defined in Android NDK headers.
// Provided by VK_KHR_android_surface
typedef VkFlags VkAndroidSurfaceCreateFlagsKHR;VkAndroidSurfaceCreateFlagsKHR is a bitmask type for setting a mask,
but is currently reserved for future use.
34.2.2. Wayland Platform
To create a VkSurfaceKHR object for a Wayland surface, call:
// Provided by VK_KHR_wayland_surface
VkResult vkCreateWaylandSurfaceKHR(
VkInstance instance,
const VkWaylandSurfaceCreateInfoKHR* pCreateInfo,
const VkAllocationCallbacks* pAllocator,
VkSurfaceKHR* pSurface);-
instanceis the instance to associate the surface with. -
pCreateInfois a pointer to a VkWaylandSurfaceCreateInfoKHR structure containing parameters affecting the creation of the surface object. -
pAllocatoris the allocator used for host memory allocated for the surface object when there is no more specific allocator available (see Memory Allocation). -
pSurfaceis a pointer to a VkSurfaceKHR handle in which the created surface object is returned.
The VkWaylandSurfaceCreateInfoKHR structure is defined as:
// Provided by VK_KHR_wayland_surface
typedef struct VkWaylandSurfaceCreateInfoKHR {
VkStructureType sType;
const void* pNext;
VkWaylandSurfaceCreateFlagsKHR flags;
struct wl_display* display;
struct wl_surface* surface;
} VkWaylandSurfaceCreateInfoKHR;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
flagsis reserved for future use. -
displayandsurfaceare pointers to the Waylandwl_displayandwl_surfaceto associate the surface with.
On Wayland, currentExtent is the special value (0xFFFFFFFF,
0xFFFFFFFF), indicating that the surface size will be determined by the
extent of a swapchain targeting the surface.
Whatever the application sets a swapchain’s imageExtent to will be the
size of the window, after the first image is presented.
minImageExtent is (1,1), and maxImageExtent is the maximum
supported surface size.
Any calls to vkGetPhysicalDeviceSurfacePresentModesKHR on a surface
created with vkCreateWaylandSurfaceKHR are required to return
VK_PRESENT_MODE_MAILBOX_KHR as one of the valid present modes.
Some Vulkan functions may send protocol over the specified wl_display
connection when using a swapchain or presentable images created from a
VkSurfaceKHR referring to a wl_surface.
Applications must therefore ensure that both the wl_display and the
wl_surface remain valid for the lifetime of any VkSwapchainKHR
objects created from a particular wl_display and wl_surface.
Also, calling vkQueuePresentKHR will result in Vulkan sending
wl_surface.commit requests to the underlying wl_surface of each
The wl_surface.attach, wl_surface.damage, and
wl_surface.commit requests must be issued by the implementation during
the call to vkQueuePresentKHR and must not be issued by the
implementation outside of vkQueuePresentKHR.
This ensures that any Wayland requests sent by the client after the call to
vkQueuePresentKHR returns will be received by the compositor after the
wl_surface.commit.
Regardless of the mode of swapchain creation, a new wl_event_queue
must be created for each successful vkCreateWaylandSurfaceKHR call,
and every Wayland object created by the implementation must be assigned to
this event queue.
If the platform provides Wayland 1.11 or greater, this must be implemented
by the use of Wayland proxy object wrappers, to avoid race conditions.
If the application wishes to synchronize any window changes with a particular frame, such requests must be sent to the Wayland display server prior to calling vkQueuePresentKHR.
// Provided by VK_KHR_wayland_surface
typedef VkFlags VkWaylandSurfaceCreateFlagsKHR;VkWaylandSurfaceCreateFlagsKHR is a bitmask type for setting a mask,
but is currently reserved for future use.
34.2.3. Win32 Platform
To create a VkSurfaceKHR object for a Win32 window, call:
// Provided by VK_KHR_win32_surface
VkResult vkCreateWin32SurfaceKHR(
VkInstance instance,
const VkWin32SurfaceCreateInfoKHR* pCreateInfo,
const VkAllocationCallbacks* pAllocator,
VkSurfaceKHR* pSurface);-
instanceis the instance to associate the surface with. -
pCreateInfois a pointer to aVkWin32SurfaceCreateInfoKHRstructure containing parameters affecting the creation of the surface object. -
pAllocatoris the allocator used for host memory allocated for the surface object when there is no more specific allocator available (see Memory Allocation). -
pSurfaceis a pointer to a VkSurfaceKHR handle in which the created surface object is returned.
The VkWin32SurfaceCreateInfoKHR structure is defined as:
// Provided by VK_KHR_win32_surface
typedef struct VkWin32SurfaceCreateInfoKHR {
VkStructureType sType;
const void* pNext;
VkWin32SurfaceCreateFlagsKHR flags;
HINSTANCE hinstance;
HWND hwnd;
} VkWin32SurfaceCreateInfoKHR;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
flagsis reserved for future use. -
hinstanceis the Win32HINSTANCEfor the window to associate the surface with. -
hwndis the Win32HWNDfor the window to associate the surface with.
With Win32, minImageExtent, maxImageExtent, and
currentExtent must always equal the window size.
The currentExtent of a Win32 surface must have both width and
height greater than 0, or both of them 0.
|
Note
Due to above restrictions,
unless VkSwapchainPresentScalingCreateInfoEXT is used to specify
handling of disparities between surface and swapchain dimensions,
it is only possible to create a new swapchain on this platform with
The window size may become (0, 0) on this platform (e.g. when the window is minimized), and so a swapchain cannot be created until the size changes. |
// Provided by VK_KHR_win32_surface
typedef VkFlags VkWin32SurfaceCreateFlagsKHR;VkWin32SurfaceCreateFlagsKHR is a bitmask type for setting a mask, but
is currently reserved for future use.
34.2.4. XCB Platform
To create a VkSurfaceKHR object for an X11 window, using the XCB
client-side library, call:
// Provided by VK_KHR_xcb_surface
VkResult vkCreateXcbSurfaceKHR(
VkInstance instance,
const VkXcbSurfaceCreateInfoKHR* pCreateInfo,
const VkAllocationCallbacks* pAllocator,
VkSurfaceKHR* pSurface);-
instanceis the instance to associate the surface with. -
pCreateInfois a pointer to aVkXcbSurfaceCreateInfoKHRstructure containing parameters affecting the creation of the surface object. -
pAllocatoris the allocator used for host memory allocated for the surface object when there is no more specific allocator available (see Memory Allocation). -
pSurfaceis a pointer to a VkSurfaceKHR handle in which the created surface object is returned.
The VkXcbSurfaceCreateInfoKHR structure is defined as:
// Provided by VK_KHR_xcb_surface
typedef struct VkXcbSurfaceCreateInfoKHR {
VkStructureType sType;
const void* pNext;
VkXcbSurfaceCreateFlagsKHR flags;
xcb_connection_t* connection;
xcb_window_t window;
} VkXcbSurfaceCreateInfoKHR;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
flagsis reserved for future use. -
connectionis a pointer to anxcb_connection_tto the X server. -
windowis thexcb_window_tfor the X11 window to associate the surface with.
With Xcb, minImageExtent, maxImageExtent, and
currentExtent must always equal the window size.
The currentExtent of an Xcb surface must have both width and
height greater than 0, or both of them 0.
|
Note
Due to above restrictions,
unless VkSwapchainPresentScalingCreateInfoEXT is used to specify
handling of disparities between surface and swapchain dimensions,
it is only possible to create a new swapchain on this platform with
The window size may become (0, 0) on this platform (e.g. when the window is minimized), and so a swapchain cannot be created until the size changes. |
Some Vulkan functions may send protocol over the specified xcb connection when using a swapchain or presentable images created from a VkSurfaceKHR referring to an xcb window. Applications must therefore ensure the xcb connection is available to Vulkan for the duration of any functions that manipulate such swapchains or their presentable images, and any functions that build or queue command buffers that operate on such presentable images. Specifically, applications using Vulkan with xcb-based swapchains must
-
Avoid holding a server grab on an xcb connection while waiting for Vulkan operations to complete using a swapchain derived from a different xcb connection referring to the same X server instance. Failing to do so may result in deadlock.
// Provided by VK_KHR_xcb_surface
typedef VkFlags VkXcbSurfaceCreateFlagsKHR;VkXcbSurfaceCreateFlagsKHR is a bitmask type for setting a mask, but
is currently reserved for future use.
34.2.5. Xlib Platform
To create a VkSurfaceKHR object for an X11 window, using the Xlib
client-side library, call:
// Provided by VK_KHR_xlib_surface
VkResult vkCreateXlibSurfaceKHR(
VkInstance instance,
const VkXlibSurfaceCreateInfoKHR* pCreateInfo,
const VkAllocationCallbacks* pAllocator,
VkSurfaceKHR* pSurface);-
instanceis the instance to associate the surface with. -
pCreateInfois a pointer to aVkXlibSurfaceCreateInfoKHRstructure containing the parameters affecting the creation of the surface object. -
pAllocatoris the allocator used for host memory allocated for the surface object when there is no more specific allocator available (see Memory Allocation). -
pSurfaceis a pointer to a VkSurfaceKHR handle in which the created surface object is returned.
The VkXlibSurfaceCreateInfoKHR structure is defined as:
// Provided by VK_KHR_xlib_surface
typedef struct VkXlibSurfaceCreateInfoKHR {
VkStructureType sType;
const void* pNext;
VkXlibSurfaceCreateFlagsKHR flags;
Display* dpy;
Window window;
} VkXlibSurfaceCreateInfoKHR;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
flagsis reserved for future use. -
dpyis a pointer to an XlibDisplayconnection to the X server. -
windowis an XlibWindowto associate the surface with.
With Xlib, minImageExtent, maxImageExtent, and
currentExtent must always equal the window size.
The currentExtent of an Xlib surface must have both width and
height greater than 0, or both of them 0.
|
Note
Due to above restrictions,
unless VkSwapchainPresentScalingCreateInfoEXT is used to specify
handling of disparities between surface and swapchain dimensions,
it is only possible to create a new swapchain on this platform with
The window size may become (0, 0) on this platform (e.g. when the window is minimized), and so a swapchain cannot be created until the size changes. |
Some Vulkan functions may send protocol over the specified Xlib
Display connection when using a swapchain or presentable images created
from a VkSurfaceKHR referring to an Xlib window.
Applications must therefore ensure the display connection is available to
Vulkan for the duration of any functions that manipulate such swapchains or
their presentable images, and any functions that build or queue command
buffers that operate on such presentable images.
Specifically, applications using Vulkan with Xlib-based swapchains must
-
Avoid holding a server grab on a display connection while waiting for Vulkan operations to complete using a swapchain derived from a different display connection referring to the same X server instance. Failing to do so may result in deadlock.
Some implementations may require threads to implement some presentation
modes so applications must call XInitThreads() before calling any
other Xlib functions.
// Provided by VK_KHR_xlib_surface
typedef VkFlags VkXlibSurfaceCreateFlagsKHR;VkXlibSurfaceCreateFlagsKHR is a bitmask type for setting a mask, but
is currently reserved for future use.
34.2.6. DirectFB Platform
To create a VkSurfaceKHR object for a DirectFB surface, call:
// Provided by VK_EXT_directfb_surface
VkResult vkCreateDirectFBSurfaceEXT(
VkInstance instance,
const VkDirectFBSurfaceCreateInfoEXT* pCreateInfo,
const VkAllocationCallbacks* pAllocator,
VkSurfaceKHR* pSurface);-
instanceis the instance to associate the surface with. -
pCreateInfois a pointer to aVkDirectFBSurfaceCreateInfoEXTstructure containing parameters affecting the creation of the surface object. -
pAllocatoris the allocator used for host memory allocated for the surface object when there is no more specific allocator available (see Memory Allocation). -
pSurfaceis a pointer to a VkSurfaceKHR handle in which the created surface object is returned.
The VkDirectFBSurfaceCreateInfoEXT structure is defined as:
// Provided by VK_EXT_directfb_surface
typedef struct VkDirectFBSurfaceCreateInfoEXT {
VkStructureType sType;
const void* pNext;
VkDirectFBSurfaceCreateFlagsEXT flags;
IDirectFB* dfb;
IDirectFBSurface* surface;
} VkDirectFBSurfaceCreateInfoEXT;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
flagsis reserved for future use. -
dfbis a pointer to theIDirectFBmain interface of DirectFB. -
surfaceis a pointer to aIDirectFBSurfacesurface interface.
With DirectFB, minImageExtent, maxImageExtent, and
currentExtent must always equal the surface size.
// Provided by VK_EXT_directfb_surface
typedef VkFlags VkDirectFBSurfaceCreateFlagsEXT;VkDirectFBSurfaceCreateFlagsEXT is a bitmask type for setting a mask,
but is currently reserved for future use.
34.2.7. Fuchsia Platform
To create a VkSurfaceKHR object for a Fuchsia ImagePipe, call:
// Provided by VK_FUCHSIA_imagepipe_surface
VkResult vkCreateImagePipeSurfaceFUCHSIA(
VkInstance instance,
const VkImagePipeSurfaceCreateInfoFUCHSIA* pCreateInfo,
const VkAllocationCallbacks* pAllocator,
VkSurfaceKHR* pSurface);-
instanceis the instance to associate with the surface. -
pCreateInfois a pointer to a VkImagePipeSurfaceCreateInfoFUCHSIA structure containing parameters affecting the creation of the surface object. -
pAllocatoris the allocator used for host memory allocated for the surface object when there is no more specific allocator available (see Memory Allocation). -
pSurfaceis a pointer to a VkSurfaceKHR handle in which the created surface object is returned.
The VkImagePipeSurfaceCreateInfoFUCHSIA structure is defined as:
// Provided by VK_FUCHSIA_imagepipe_surface
typedef struct VkImagePipeSurfaceCreateInfoFUCHSIA {
VkStructureType sType;
const void* pNext;
VkImagePipeSurfaceCreateFlagsFUCHSIA flags;
zx_handle_t imagePipeHandle;
} VkImagePipeSurfaceCreateInfoFUCHSIA;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
flagsis reserved for future use. -
imagePipeHandleis azx_handle_treferring to the ImagePipe to associate with the surface.
On Fuchsia, the surface currentExtent is the special value
(0xFFFFFFFF, 0xFFFFFFFF), indicating that the surface size will be
determined by the extent of a swapchain targeting the surface.
// Provided by VK_FUCHSIA_imagepipe_surface
typedef VkFlags VkImagePipeSurfaceCreateFlagsFUCHSIA;VkImagePipeSurfaceCreateFlagsFUCHSIA is a bitmask type for setting a
mask, but is currently reserved for future use.
34.2.8. Google Games Platform
To create a VkSurfaceKHR object for a Google Games Platform stream
descriptor, call:
// Provided by VK_GGP_stream_descriptor_surface
VkResult vkCreateStreamDescriptorSurfaceGGP(
VkInstance instance,
const VkStreamDescriptorSurfaceCreateInfoGGP* pCreateInfo,
const VkAllocationCallbacks* pAllocator,
VkSurfaceKHR* pSurface);-
instanceis the instance to associate with the surface. -
pCreateInfois a pointer to aVkStreamDescriptorSurfaceCreateInfoGGPstructure containing parameters that affect the creation of the surface object. -
pAllocatoris the allocator used for host memory allocated for the surface object when there is no more specific allocator available (see Memory Allocation). -
pSurfaceis a pointer to a VkSurfaceKHR handle in which the created surface object is returned.
The VkStreamDescriptorSurfaceCreateInfoGGP structure is defined as:
// Provided by VK_GGP_stream_descriptor_surface
typedef struct VkStreamDescriptorSurfaceCreateInfoGGP {
VkStructureType sType;
const void* pNext;
VkStreamDescriptorSurfaceCreateFlagsGGP flags;
GgpStreamDescriptor streamDescriptor;
} VkStreamDescriptorSurfaceCreateInfoGGP;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
flagsis reserved for future use. -
streamDescriptoris aGgpStreamDescriptorreferring to the GGP stream descriptor to associate with the surface.
On Google Games Platform, the surface extents are dynamic.
The minImageExtent will never be greater than 1080p and the
maxImageExtent will never be less than 1080p.
The currentExtent will reflect the current optimal resolution.
Applications are expected to choose an appropriate size for the swapchain’s
imageExtent, within the bounds of the surface.
Using the surface’s currentExtent will offer the best performance and
quality.
When a swapchain’s imageExtent does not match the surface’s
currentExtent, the presentable images are scaled to the surface’s
dimensions during presentation if possible and VK_SUBOPTIMAL_KHR is
returned, otherwise presentation fails with VK_ERROR_OUT_OF_DATE_KHR.
// Provided by VK_GGP_stream_descriptor_surface
typedef VkFlags VkStreamDescriptorSurfaceCreateFlagsGGP;VkStreamDescriptorSurfaceCreateFlagsGGP is a bitmask type for setting
a mask, but is currently reserved for future use.
34.2.9. iOS Platform
To create a VkSurfaceKHR object for an iOS UIView or
CAMetalLayer, call:
// Provided by VK_MVK_ios_surface
VkResult vkCreateIOSSurfaceMVK(
VkInstance instance,
const VkIOSSurfaceCreateInfoMVK* pCreateInfo,
const VkAllocationCallbacks* pAllocator,
VkSurfaceKHR* pSurface);|
Note
The |
-
instanceis the instance with which to associate the surface. -
pCreateInfois a pointer to a VkIOSSurfaceCreateInfoMVK structure containing parameters affecting the creation of the surface object. -
pAllocatoris the allocator used for host memory allocated for the surface object when there is no more specific allocator available (see Memory Allocation). -
pSurfaceis a pointer to a VkSurfaceKHR handle in which the created surface object is returned.
The VkIOSSurfaceCreateInfoMVK structure is defined as:
// Provided by VK_MVK_ios_surface
typedef struct VkIOSSurfaceCreateInfoMVK {
VkStructureType sType;
const void* pNext;
VkIOSSurfaceCreateFlagsMVK flags;
const void* pView;
} VkIOSSurfaceCreateInfoMVK;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
flagsis reserved for future use. -
pViewis a reference to either a CAMetalLayer object or aUIViewobject.
// Provided by VK_MVK_ios_surface
typedef VkFlags VkIOSSurfaceCreateFlagsMVK;VkIOSSurfaceCreateFlagsMVK is a bitmask type for setting a mask, but
is currently reserved for future use.
34.2.10. macOS Platform
To create a VkSurfaceKHR object for a macOS NSView or
CAMetalLayer, call:
// Provided by VK_MVK_macos_surface
VkResult vkCreateMacOSSurfaceMVK(
VkInstance instance,
const VkMacOSSurfaceCreateInfoMVK* pCreateInfo,
const VkAllocationCallbacks* pAllocator,
VkSurfaceKHR* pSurface);|
Note
The |
-
instanceis the instance with which to associate the surface. -
pCreateInfois a pointer to a VkMacOSSurfaceCreateInfoMVK structure containing parameters affecting the creation of the surface object. -
pAllocatoris the allocator used for host memory allocated for the surface object when there is no more specific allocator available (see Memory Allocation). -
pSurfaceis a pointer to a VkSurfaceKHR handle in which the created surface object is returned.
The VkMacOSSurfaceCreateInfoMVK structure is defined as:
// Provided by VK_MVK_macos_surface
typedef struct VkMacOSSurfaceCreateInfoMVK {
VkStructureType sType;
const void* pNext;
VkMacOSSurfaceCreateFlagsMVK flags;
const void* pView;
} VkMacOSSurfaceCreateInfoMVK;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
flagsis reserved for future use. -
pViewis a reference to either a CAMetalLayer object or anNSViewobject.
// Provided by VK_MVK_macos_surface
typedef VkFlags VkMacOSSurfaceCreateFlagsMVK;VkMacOSSurfaceCreateFlagsMVK is a bitmask type for setting a mask, but
is currently reserved for future use.
34.2.11. VI Platform
To create a VkSurfaceKHR object for an nn::vi::Layer,
query the layer’s native handle using
nn::vi::GetNativeWindow, and then call:
// Provided by VK_NN_vi_surface
VkResult vkCreateViSurfaceNN(
VkInstance instance,
const VkViSurfaceCreateInfoNN* pCreateInfo,
const VkAllocationCallbacks* pAllocator,
VkSurfaceKHR* pSurface);-
instanceis the instance with which to associate the surface. -
pCreateInfois a pointer to aVkViSurfaceCreateInfoNNstructure containing parameters affecting the creation of the surface object. -
pAllocatoris the allocator used for host memory allocated for the surface object when there is no more specific allocator available (see Memory Allocation). -
pSurfaceis a pointer to a VkSurfaceKHR handle in which the created surface object is returned.
During the lifetime of a surface created using a particular
nn::vi::NativeWindowHandle, applications must not attempt to
create another surface for the same nn::vi::Layer or attempt
to connect to the same nn::vi::Layer through other platform
mechanisms.
If the native window is created with a specified size, currentExtent
will reflect that size.
In this case, applications should use the same size for the swapchain’s
imageExtent.
Otherwise, the currentExtent will have the special value
(0xFFFFFFFF, 0xFFFFFFFF), indicating that applications are expected to
choose an appropriate size for the swapchain’s imageExtent (e.g., by
matching the result of a call to
nn::vi::GetDisplayResolution).
The VkViSurfaceCreateInfoNN structure is defined as:
// Provided by VK_NN_vi_surface
typedef struct VkViSurfaceCreateInfoNN {
VkStructureType sType;
const void* pNext;
VkViSurfaceCreateFlagsNN flags;
void* window;
} VkViSurfaceCreateInfoNN;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
flagsis reserved for future use. -
windowis thenn::vi::NativeWindowHandlefor thenn::vi::Layerwith which to associate the surface.
// Provided by VK_NN_vi_surface
typedef VkFlags VkViSurfaceCreateFlagsNN;VkViSurfaceCreateFlagsNN is a bitmask type for setting a mask, but is
currently reserved for future use.
34.2.12. Metal Platform
To create a VkSurfaceKHR object for a CAMetalLayer, call:
// Provided by VK_EXT_metal_surface
VkResult vkCreateMetalSurfaceEXT(
VkInstance instance,
const VkMetalSurfaceCreateInfoEXT* pCreateInfo,
const VkAllocationCallbacks* pAllocator,
VkSurfaceKHR* pSurface);-
instanceis the instance with which to associate the surface. -
pCreateInfois a pointer to a VkMetalSurfaceCreateInfoEXT structure specifying parameters affecting the creation of the surface object. -
pAllocatoris the allocator used for host memory allocated for the surface object when there is no more specific allocator available (see Memory Allocation). -
pSurfaceis a pointer to aVkSurfaceKHRhandle in which the created surface object is returned.
The VkMetalSurfaceCreateInfoEXT structure is defined as:
// Provided by VK_EXT_metal_surface
typedef struct VkMetalSurfaceCreateInfoEXT {
VkStructureType sType;
const void* pNext;
VkMetalSurfaceCreateFlagsEXT flags;
const CAMetalLayer* pLayer;
} VkMetalSurfaceCreateInfoEXT;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
flagsis reserved for future use. -
pLayeris a reference to a CAMetalLayer object representing a renderable surface.
To remove an unnecessary compile time dependency, an incomplete type definition of CAMetalLayer is provided in the Vulkan headers:
// Provided by VK_EXT_metal_surface
#ifdef __OBJC__
@class CAMetalLayer;
#else
typedef void CAMetalLayer;
#endif
The actual CAMetalLayer type is defined in the QuartzCore framework.
// Provided by VK_EXT_metal_surface
typedef VkFlags VkMetalSurfaceCreateFlagsEXT;VkMetalSurfaceCreateFlagsEXT is a bitmask type for setting a mask, but
is currently reserved for future use.
34.2.13. QNX Screen Platform
To create a VkSurfaceKHR object for a QNX Screen surface, call:
// Provided by VK_QNX_screen_surface
VkResult vkCreateScreenSurfaceQNX(
VkInstance instance,
const VkScreenSurfaceCreateInfoQNX* pCreateInfo,
const VkAllocationCallbacks* pAllocator,
VkSurfaceKHR* pSurface);-
instanceis the instance to associate the surface with. -
pCreateInfois a pointer to a VkScreenSurfaceCreateInfoQNX structure containing parameters affecting the creation of the surface object. -
pAllocatoris the allocator used for host memory allocated for the surface object when there is no more specific allocator available (see Memory Allocation). -
pSurfaceis a pointer to a VkSurfaceKHR handle in which the created surface object is returned.
The VkScreenSurfaceCreateInfoQNX structure is defined as:
// Provided by VK_QNX_screen_surface
typedef struct VkScreenSurfaceCreateInfoQNX {
VkStructureType sType;
const void* pNext;
VkScreenSurfaceCreateFlagsQNX flags;
struct _screen_context* context;
struct _screen_window* window;
} VkScreenSurfaceCreateInfoQNX;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
flagsis reserved for future use. -
contextandwindoware QNX Screencontextandwindowto associate the surface with.
// Provided by VK_QNX_screen_surface
typedef VkFlags VkScreenSurfaceCreateFlagsQNX;VkScreenSurfaceCreateFlagsQNX is a bitmask type for setting a mask,
but is currently reserved for future use.
34.2.14. Platform-Independent Information
Once created, VkSurfaceKHR objects can be used in this and other
extensions, in particular the VK_KHR_swapchain extension.
Several WSI functions return VK_ERROR_SURFACE_LOST_KHR if the surface
becomes no longer available.
After such an error, the surface (and any child swapchain, if one exists)
should be destroyed, as there is no way to restore them to a not-lost
state.
Applications may attempt to create a new VkSurfaceKHR using the same
native platform window object, but whether such re-creation will succeed is
platform-dependent and may depend on the reason the surface became
unavailable.
A lost surface does not otherwise cause devices to be
lost.
To destroy a VkSurfaceKHR object, call:
// Provided by VK_KHR_surface
void vkDestroySurfaceKHR(
VkInstance instance,
VkSurfaceKHR surface,
const VkAllocationCallbacks* pAllocator);-
instanceis the instance used to create the surface. -
surfaceis the surface to destroy. -
pAllocatoris the allocator used for host memory allocated for the surface object when there is no more specific allocator available (see Memory Allocation).
Destroying a VkSurfaceKHR merely severs the connection between Vulkan
and the native surface, and does not imply destroying the native surface,
closing a window, or similar behavior.
34.3. Presenting Directly to Display Devices
In some environments applications can also present Vulkan rendering
directly to display devices without using an intermediate windowing system.
This can be useful for embedded applications, or implementing the
rendering/presentation backend of a windowing system using Vulkan.
The VK_KHR_display extension provides the functionality necessary
to enumerate display devices and create VkSurfaceKHR objects that
target displays.
34.3.1. Display Enumeration
Displays are represented by VkDisplayKHR handles:
// Provided by VK_KHR_display
VK_DEFINE_NON_DISPATCHABLE_HANDLE(VkDisplayKHR)Various functions are provided for enumerating the available display devices present on a Vulkan physical device. To query information about the available displays, call:
// Provided by VK_KHR_display
VkResult vkGetPhysicalDeviceDisplayPropertiesKHR(
VkPhysicalDevice physicalDevice,
uint32_t* pPropertyCount,
VkDisplayPropertiesKHR* pProperties);-
physicalDeviceis a physical device. -
pPropertyCountis a pointer to an integer related to the number of display devices available or queried, as described below. -
pPropertiesis eitherNULLor a pointer to an array ofVkDisplayPropertiesKHRstructures.
If pProperties is NULL, then the number of display devices available
for physicalDevice is returned in pPropertyCount.
Otherwise, pPropertyCount must point to a variable set by the user to
the number of elements in the pProperties array, and on return the
variable is overwritten with the number of structures actually written to
pProperties.
If the value of pPropertyCount is less than the number of display
devices for physicalDevice, at most pPropertyCount structures
will be written, and VK_INCOMPLETE will be returned instead of
VK_SUCCESS, to indicate that not all the available properties were
returned.
The VkDisplayPropertiesKHR structure is defined as:
// Provided by VK_KHR_display
typedef struct VkDisplayPropertiesKHR {
VkDisplayKHR display;
const char* displayName;
VkExtent2D physicalDimensions;
VkExtent2D physicalResolution;
VkSurfaceTransformFlagsKHR supportedTransforms;
VkBool32 planeReorderPossible;
VkBool32 persistentContent;
} VkDisplayPropertiesKHR;-
displayis a handle that is used to refer to the display described here. This handle will be valid for the lifetime of the Vulkan instance. -
displayNameisNULLor a pointer to a null-terminated UTF-8 string containing the name of the display. Generally, this will be the name provided by the display’s EDID. IfNULL, no suitable name is available. If notNULL, the string pointed to must remain accessible and unmodified as long asdisplayis valid. -
physicalDimensionsdescribes the physical width and height of the visible portion of the display, in millimeters. -
physicalResolutiondescribes the physical, native, or preferred resolution of the display.
|
Note
For devices which have no natural value to return here, implementations should return the maximum resolution supported. |
-
supportedTransformsis a bitmask of VkSurfaceTransformFlagBitsKHR describing which transforms are supported by this display. -
planeReorderPossibletells whether the planes on this display can have their z order changed. If this isVK_TRUE, the application can re-arrange the planes on this display in any order relative to each other. -
persistentContenttells whether the display supports self-refresh/internal buffering. If this is true, the application can submit persistent present operations on swapchains created against this display.
|
Note
Persistent presents may have higher latency, and may use less power when the screen content is updated infrequently, or when only a portion of the screen needs to be updated in most frames. |
To query information about the available displays, call:
// Provided by VK_KHR_get_display_properties2
VkResult vkGetPhysicalDeviceDisplayProperties2KHR(
VkPhysicalDevice physicalDevice,
uint32_t* pPropertyCount,
VkDisplayProperties2KHR* pProperties);-
physicalDeviceis a physical device. -
pPropertyCountis a pointer to an integer related to the number of display devices available or queried, as described below. -
pPropertiesis eitherNULLor a pointer to an array ofVkDisplayProperties2KHRstructures.
vkGetPhysicalDeviceDisplayProperties2KHR behaves similarly to
vkGetPhysicalDeviceDisplayPropertiesKHR, with the ability to return
extended information via chained output structures.
The VkDisplayProperties2KHR structure is defined as:
// Provided by VK_KHR_get_display_properties2
typedef struct VkDisplayProperties2KHR {
VkStructureType sType;
void* pNext;
VkDisplayPropertiesKHR displayProperties;
} VkDisplayProperties2KHR;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
displayPropertiesis a VkDisplayPropertiesKHR structure.
Acquiring and Releasing Displays
On some platforms, access to displays is limited to a single process or native driver instance. On such platforms, some or all of the displays may not be available to Vulkan if they are already in use by a native windowing system or other application.
To acquire permission to directly access a display in Vulkan from an X11 server, call:
// Provided by VK_EXT_acquire_xlib_display
VkResult vkAcquireXlibDisplayEXT(
VkPhysicalDevice physicalDevice,
Display* dpy,
VkDisplayKHR display);-
physicalDeviceThe physical device the display is on. -
dpyA connection to the X11 server that currently ownsdisplay. -
displayThe display the caller wishes to control in Vulkan.
All permissions necessary to control the display are granted to the Vulkan
instance associated with physicalDevice until the display is released
or the X11 connection specified by dpy is terminated.
Permission to access the display may be temporarily revoked during periods
when the X11 server from which control was acquired itself loses access to
display.
During such periods, operations which require access to the display must
fail with an appropriate error code.
If the X11 server associated with dpy does not own display, or
if permission to access it has already been acquired by another entity, the
call must return the error code VK_ERROR_INITIALIZATION_FAILED.
|
Note
One example of when an X11 server loses access to a display is when it loses ownership of its virtual terminal. |
When acquiring displays from an X11 server, an application may also wish to
enumerate and identify them using a native handle rather than a
VkDisplayKHR handle.
To determine the VkDisplayKHR handle corresponding to an X11 RandR
Output, call:
// Provided by VK_EXT_acquire_xlib_display
VkResult vkGetRandROutputDisplayEXT(
VkPhysicalDevice physicalDevice,
Display* dpy,
RROutput rrOutput,
VkDisplayKHR* pDisplay);-
physicalDeviceThe physical device to query the display handle on. -
dpyA connection to the X11 server from whichrrOutputwas queried. -
rrOutputAn X11 RandR output ID. -
pDisplayThe corresponding VkDisplayKHR handle will be returned here.
If there is no VkDisplayKHR corresponding to rrOutput on
physicalDevice, VK_NULL_HANDLE must be returned in
pDisplay.
To acquire permission to directly access a display in Vulkan on Windows 10, call:
// Provided by VK_NV_acquire_winrt_display
VkResult vkAcquireWinrtDisplayNV(
VkPhysicalDevice physicalDevice,
VkDisplayKHR display);-
physicalDeviceThe physical device the display is on. -
displayThe display the caller wishes to control in Vulkan.
All permissions necessary to control the display are granted to the Vulkan
instance associated with physicalDevice until the display is released
or the application is terminated.
Permission to access the display may be revoked by events that cause
Windows 10 itself to lose access to display.
If this has happened, operations which require access to the display must
fail with an appropriate error code.
If permission to access display has already been acquired by another
entity, the call must return the error code
VK_ERROR_INITIALIZATION_FAILED.
|
Note
The Vulkan instance acquires control of a “winrt::Windows::Devices::Display::Core::DisplayTarget” by performing an operation equivalent to “winrt::Windows::Devices::Display::Core::DisplayManager.TryAcquireTarget()” on the “DisplayTarget”. |
|
Note
One example of when Windows 10 loses access to a display is when the display is hot-unplugged. |
|
Note
One example of when a display has already been acquired by another entity is when the Windows desktop compositor (DWM) is in control of the display. Beginning with Windows 10 version 2004 it is possible to cause DWM to release a display by using the “Advanced display settings” sub-page of the “Display settings” control panel. vkAcquireWinrtDisplayNV does not itself cause DWM to release a display; this action must be performed outside of Vulkan. |
When acquiring displays on Windows 10, an application may also wish to
enumerate and identify them using a native handle rather than a
VkDisplayKHR handle.
To determine the VkDisplayKHR handle corresponding to a
“winrt::Windows::Devices::Display::Core::DisplayTarget”,
call:
// Provided by VK_NV_acquire_winrt_display
VkResult vkGetWinrtDisplayNV(
VkPhysicalDevice physicalDevice,
uint32_t deviceRelativeId,
VkDisplayKHR* pDisplay);-
physicalDeviceThe physical device on which to query the display handle. -
deviceRelativeIdThe value of the “AdapterRelativeId” property of a “DisplayTarget” that is enumerated by a “DisplayAdapter” with an “Id” property matching thedeviceLUIDproperty of a VkPhysicalDeviceIDProperties forphysicalDevice. -
pDisplayThe corresponding VkDisplayKHR handle will be returned here.
If there is no VkDisplayKHR corresponding to deviceRelativeId on
physicalDevice, VK_NULL_HANDLE must be returned in
pDisplay.
To acquire permission to directly a display in Vulkan from the Direct Rendering Manager (DRM) interface, call:
// Provided by VK_EXT_acquire_drm_display
VkResult vkAcquireDrmDisplayEXT(
VkPhysicalDevice physicalDevice,
int32_t drmFd,
VkDisplayKHR display);-
physicalDeviceThe physical device the display is on. -
drmFdDRM primary file descriptor. -
displayThe display the caller wishes Vulkan to control.
All permissions necessary to control the display are granted to the Vulkan
instance associated with the provided physicalDevice until the display
is either released or the connector is unplugged.
The provided drmFd must correspond to the one owned by the
physicalDevice.
If not, the error code VK_ERROR_UNKNOWN must be returned.
The DRM FD must have DRM master permissions.
If any error is encountered during the acquisition of the display, the call
must return the error code VK_ERROR_INITIALIZATION_FAILED.
The provided DRM fd should not be closed before the display is released, attempting to do it may result in undefined behaviour.
Before acquiring a display from the DRM interface, the caller may want to
select a specific VkDisplayKHR handle by identifying it using a
connectorId.
To do so, call:
// Provided by VK_EXT_acquire_drm_display
VkResult vkGetDrmDisplayEXT(
VkPhysicalDevice physicalDevice,
int32_t drmFd,
uint32_t connectorId,
VkDisplayKHR* display);-
physicalDeviceThe physical device to query the display from. -
drmFdDRM primary file descriptor. -
connectorIdIdentifier of the specified DRM connector. -
displayThe corresponding VkDisplayKHR handle will be returned here.
If there is no VkDisplayKHR corresponding to the connectorId on
the physicalDevice, the returning display must be set to
VK_NULL_HANDLE.
The provided drmFd must correspond to the one owned by the
physicalDevice.
If not, the error code VK_ERROR_UNKNOWN must be returned.
Master permissions are not required, because the file descriptor is just
used for information gathering purposes.
The given connectorId must be a resource owned by the provided
drmFd.
If not, the error code VK_ERROR_UNKNOWN must be returned.
If any error is encountered during the identification of the display, the
call must return the error code VK_ERROR_INITIALIZATION_FAILED.
To release a previously acquired display, call:
// Provided by VK_EXT_direct_mode_display
VkResult vkReleaseDisplayEXT(
VkPhysicalDevice physicalDevice,
VkDisplayKHR display);-
physicalDeviceThe physical device the display is on. -
displayThe display to release control of.
Display Planes
Images are presented to individual planes on a display. Devices must support at least one plane on each display. Planes can be stacked and blended to composite multiple images on one display. Devices may support only a fixed stacking order and fixed mapping between planes and displays, or they may allow arbitrary application specified stacking orders and mappings between planes and displays. To query the properties of device display planes, call:
// Provided by VK_KHR_display
VkResult vkGetPhysicalDeviceDisplayPlanePropertiesKHR(
VkPhysicalDevice physicalDevice,
uint32_t* pPropertyCount,
VkDisplayPlanePropertiesKHR* pProperties);-
physicalDeviceis a physical device. -
pPropertyCountis a pointer to an integer related to the number of display planes available or queried, as described below. -
pPropertiesis eitherNULLor a pointer to an array ofVkDisplayPlanePropertiesKHRstructures.
If pProperties is NULL, then the number of display planes available
for physicalDevice is returned in pPropertyCount.
Otherwise, pPropertyCount must point to a variable set by the user to
the number of elements in the pProperties array, and on return the
variable is overwritten with the number of structures actually written to
pProperties.
If the value of pPropertyCount is less than the number of display
planes for physicalDevice, at most pPropertyCount structures
will be written.
The VkDisplayPlanePropertiesKHR structure is defined as:
// Provided by VK_KHR_display
typedef struct VkDisplayPlanePropertiesKHR {
VkDisplayKHR currentDisplay;
uint32_t currentStackIndex;
} VkDisplayPlanePropertiesKHR;-
currentDisplayis the handle of the display the plane is currently associated with. If the plane is not currently attached to any displays, this will be VK_NULL_HANDLE. -
currentStackIndexis the current z-order of the plane. This will be between 0 and the value returned byvkGetPhysicalDeviceDisplayPlanePropertiesKHRinpPropertyCount.
To query the properties of a device’s display planes, call:
// Provided by VK_KHR_get_display_properties2
VkResult vkGetPhysicalDeviceDisplayPlaneProperties2KHR(
VkPhysicalDevice physicalDevice,
uint32_t* pPropertyCount,
VkDisplayPlaneProperties2KHR* pProperties);-
physicalDeviceis a physical device. -
pPropertyCountis a pointer to an integer related to the number of display planes available or queried, as described below. -
pPropertiesis eitherNULLor a pointer to an array ofVkDisplayPlaneProperties2KHRstructures.
vkGetPhysicalDeviceDisplayPlaneProperties2KHR behaves similarly to
vkGetPhysicalDeviceDisplayPlanePropertiesKHR, with the ability to
return extended information via chained output structures.
The VkDisplayPlaneProperties2KHR structure is defined as:
// Provided by VK_KHR_get_display_properties2
typedef struct VkDisplayPlaneProperties2KHR {
VkStructureType sType;
void* pNext;
VkDisplayPlanePropertiesKHR displayPlaneProperties;
} VkDisplayPlaneProperties2KHR;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
displayPlanePropertiesis a VkDisplayPlanePropertiesKHR structure.
To determine which displays a plane is usable with, call
// Provided by VK_KHR_display
VkResult vkGetDisplayPlaneSupportedDisplaysKHR(
VkPhysicalDevice physicalDevice,
uint32_t planeIndex,
uint32_t* pDisplayCount,
VkDisplayKHR* pDisplays);-
physicalDeviceis a physical device. -
planeIndexis the plane which the application wishes to use, and must be in the range [0, physical device plane count - 1]. -
pDisplayCountis a pointer to an integer related to the number of displays available or queried, as described below. -
pDisplaysis eitherNULLor a pointer to an array ofVkDisplayKHRhandles.
If pDisplays is NULL, then the number of displays usable with the
specified planeIndex for physicalDevice is returned in
pDisplayCount.
Otherwise, pDisplayCount must point to a variable set by the user to
the number of elements in the pDisplays array, and on return the
variable is overwritten with the number of handles actually written to
pDisplays.
If the value of pDisplayCount is less than the number of usable
display-plane pairs for physicalDevice, at most pDisplayCount
handles will be written, and VK_INCOMPLETE will be returned instead of
VK_SUCCESS, to indicate that not all the available pairs were
returned.
Additional properties of displays are queried using specialized query functions.
Display Modes
Display modes are represented by VkDisplayModeKHR handles:
// Provided by VK_KHR_display
VK_DEFINE_NON_DISPATCHABLE_HANDLE(VkDisplayModeKHR)Each display has one or more supported modes associated with it by default. These built-in modes are queried by calling:
// Provided by VK_KHR_display
VkResult vkGetDisplayModePropertiesKHR(
VkPhysicalDevice physicalDevice,
VkDisplayKHR display,
uint32_t* pPropertyCount,
VkDisplayModePropertiesKHR* pProperties);-
physicalDeviceis the physical device associated withdisplay. -
displayis the display to query. -
pPropertyCountis a pointer to an integer related to the number of display modes available or queried, as described below. -
pPropertiesis eitherNULLor a pointer to an array ofVkDisplayModePropertiesKHRstructures.
If pProperties is NULL, then the number of display modes available
on the specified display for physicalDevice is returned in
pPropertyCount.
Otherwise, pPropertyCount must point to a variable set by the user to
the number of elements in the pProperties array, and on return the
variable is overwritten with the number of structures actually written to
pProperties.
If the value of pPropertyCount is less than the number of display
modes for physicalDevice, at most pPropertyCount structures will
be written, and VK_INCOMPLETE will be returned instead of
VK_SUCCESS, to indicate that not all the available display modes were
returned.
The VkDisplayModePropertiesKHR structure is defined as:
// Provided by VK_KHR_display
typedef struct VkDisplayModePropertiesKHR {
VkDisplayModeKHR displayMode;
VkDisplayModeParametersKHR parameters;
} VkDisplayModePropertiesKHR;-
displayModeis a handle to the display mode described in this structure. This handle will be valid for the lifetime of the Vulkan instance. -
parametersis a VkDisplayModeParametersKHR structure describing the display parameters associated withdisplayMode.
// Provided by VK_KHR_display
typedef VkFlags VkDisplayModeCreateFlagsKHR;VkDisplayModeCreateFlagsKHR is a bitmask type for setting a mask, but
is currently reserved for future use.
To query the properties of a device’s built-in display modes, call:
// Provided by VK_KHR_get_display_properties2
VkResult vkGetDisplayModeProperties2KHR(
VkPhysicalDevice physicalDevice,
VkDisplayKHR display,
uint32_t* pPropertyCount,
VkDisplayModeProperties2KHR* pProperties);-
physicalDeviceis the physical device associated withdisplay. -
displayis the display to query. -
pPropertyCountis a pointer to an integer related to the number of display modes available or queried, as described below. -
pPropertiesis eitherNULLor a pointer to an array ofVkDisplayModeProperties2KHRstructures.
vkGetDisplayModeProperties2KHR behaves similarly to
vkGetDisplayModePropertiesKHR, with the ability to return extended
information via chained output structures.
The VkDisplayModeProperties2KHR structure is defined as:
// Provided by VK_KHR_get_display_properties2
typedef struct VkDisplayModeProperties2KHR {
VkStructureType sType;
void* pNext;
VkDisplayModePropertiesKHR displayModeProperties;
} VkDisplayModeProperties2KHR;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
displayModePropertiesis a VkDisplayModePropertiesKHR structure.
The VkDisplayModeParametersKHR structure is defined as:
// Provided by VK_KHR_display
typedef struct VkDisplayModeParametersKHR {
VkExtent2D visibleRegion;
uint32_t refreshRate;
} VkDisplayModeParametersKHR;-
visibleRegionis the 2D extents of the visible region. -
refreshRateis auint32_tthat is the number of times the display is refreshed each second multiplied by 1000.
|
Note
For example, a 60Hz display mode would report a |
Additional modes may also be created by calling:
// Provided by VK_KHR_display
VkResult vkCreateDisplayModeKHR(
VkPhysicalDevice physicalDevice,
VkDisplayKHR display,
const VkDisplayModeCreateInfoKHR* pCreateInfo,
const VkAllocationCallbacks* pAllocator,
VkDisplayModeKHR* pMode);-
physicalDeviceis the physical device associated withdisplay. -
displayis the display to create an additional mode for. -
pCreateInfois a pointer to a VkDisplayModeCreateInfoKHR structure describing the new mode to create. -
pAllocatoris the allocator used for host memory allocated for the display mode object when there is no more specific allocator available (see Memory Allocation). -
pModeis a pointer to a VkDisplayModeKHR handle in which the mode created is returned.
The VkDisplayModeCreateInfoKHR structure is defined as:
// Provided by VK_KHR_display
typedef struct VkDisplayModeCreateInfoKHR {
VkStructureType sType;
const void* pNext;
VkDisplayModeCreateFlagsKHR flags;
VkDisplayModeParametersKHR parameters;
} VkDisplayModeCreateInfoKHR;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
flagsis reserved for future use, and must be zero. -
parametersis a VkDisplayModeParametersKHR structure describing the display parameters to use in creating the new mode. If the parameters are not compatible with the specified display, the implementation must returnVK_ERROR_INITIALIZATION_FAILED.
Applications that wish to present directly to a display must select which layer, or “plane” of the display they wish to target, and a mode to use with the display. Each display supports at least one plane. The capabilities of a given mode and plane combination are determined by calling:
// Provided by VK_KHR_display
VkResult vkGetDisplayPlaneCapabilitiesKHR(
VkPhysicalDevice physicalDevice,
VkDisplayModeKHR mode,
uint32_t planeIndex,
VkDisplayPlaneCapabilitiesKHR* pCapabilities);-
physicalDeviceis the physical device associated with the display specified bymode -
modeis the display mode the application intends to program when using the specified plane. Note this parameter also implicitly specifies a display. -
planeIndexis the plane which the application intends to use with the display, and is less than the number of display planes supported by the device. -
pCapabilitiesis a pointer to a VkDisplayPlaneCapabilitiesKHR structure in which the capabilities are returned.
The VkDisplayPlaneCapabilitiesKHR structure is defined as:
// Provided by VK_KHR_display
typedef struct VkDisplayPlaneCapabilitiesKHR {
VkDisplayPlaneAlphaFlagsKHR supportedAlpha;
VkOffset2D minSrcPosition;
VkOffset2D maxSrcPosition;
VkExtent2D minSrcExtent;
VkExtent2D maxSrcExtent;
VkOffset2D minDstPosition;
VkOffset2D maxDstPosition;
VkExtent2D minDstExtent;
VkExtent2D maxDstExtent;
} VkDisplayPlaneCapabilitiesKHR;-
supportedAlphais a bitmask of VkDisplayPlaneAlphaFlagBitsKHR describing the supported alpha blending modes. -
minSrcPositionis the minimum source rectangle offset supported by this plane using the specified mode. -
maxSrcPositionis the maximum source rectangle offset supported by this plane using the specified mode. Thexandycomponents ofmaxSrcPositionmust each be greater than or equal to thexandycomponents ofminSrcPosition, respectively. -
minSrcExtentis the minimum source rectangle size supported by this plane using the specified mode. -
maxSrcExtentis the maximum source rectangle size supported by this plane using the specified mode. -
minDstPosition,maxDstPosition,minDstExtent,maxDstExtentall have similar semantics to their corresponding*Src*equivalents, but apply to the output region within the mode rather than the input region within the source image. Unlike the*Src*offsets,minDstPositionandmaxDstPositionmay contain negative values.
The minimum and maximum position and extent fields describe the
implementation limits, if any, as they apply to the specified display mode
and plane.
Vendors may support displaying a subset of a swapchain’s presentable images
on the specified display plane.
This is expressed by returning minSrcPosition, maxSrcPosition,
minSrcExtent, and maxSrcExtent values that indicate a range of
possible positions and sizes which may be used to specify the region within
the presentable images that source pixels will be read from when creating a
swapchain on the specified display mode and plane.
Vendors may also support mapping the presentable images’ content to a
subset or superset of the visible region in the specified display mode.
This is expressed by returning minDstPosition, maxDstPosition,
minDstExtent and maxDstExtent values that indicate a range of
possible positions and sizes which may be used to describe the region
within the display mode that the source pixels will be mapped to.
Other vendors may support only a 1-1 mapping between pixels in the
presentable images and the display mode.
This may be indicated by returning (0,0) for minSrcPosition,
maxSrcPosition, minDstPosition, and maxDstPosition, and
(display mode width, display mode height) for minSrcExtent,
maxSrcExtent, minDstExtent, and maxDstExtent.
The value supportedAlpha must contain at least one valid
VkDisplayPlaneAlphaFlagBitsKHR bit.
These values indicate the limits of the implementation’s individual fields.
Not all combinations of values within the offset and extent ranges returned
in VkDisplayPlaneCapabilitiesKHR are guaranteed to be supported.
Presentation requests specifying unsupported combinations may fail.
To query the capabilities of a given mode and plane combination, call:
// Provided by VK_KHR_get_display_properties2
VkResult vkGetDisplayPlaneCapabilities2KHR(
VkPhysicalDevice physicalDevice,
const VkDisplayPlaneInfo2KHR* pDisplayPlaneInfo,
VkDisplayPlaneCapabilities2KHR* pCapabilities);-
physicalDeviceis the physical device associated withpDisplayPlaneInfo. -
pDisplayPlaneInfois a pointer to a VkDisplayPlaneInfo2KHR structure describing the plane and mode. -
pCapabilitiesis a pointer to a VkDisplayPlaneCapabilities2KHR structure in which the capabilities are returned.
vkGetDisplayPlaneCapabilities2KHR behaves similarly to
vkGetDisplayPlaneCapabilitiesKHR, with the ability to specify extended
inputs via chained input structures, and to return extended information via
chained output structures.
The VkDisplayPlaneInfo2KHR structure is defined as:
// Provided by VK_KHR_get_display_properties2
typedef struct VkDisplayPlaneInfo2KHR {
VkStructureType sType;
const void* pNext;
VkDisplayModeKHR mode;
uint32_t planeIndex;
} VkDisplayPlaneInfo2KHR;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
modeis the display mode the application intends to program when using the specified plane.
|
Note
This parameter also implicitly specifies a display. |
-
planeIndexis the plane which the application intends to use with the display.
The members of VkDisplayPlaneInfo2KHR correspond to the arguments to
vkGetDisplayPlaneCapabilitiesKHR, with sType and pNext
added for extensibility.
The VkDisplayPlaneCapabilities2KHR structure is defined as:
// Provided by VK_KHR_get_display_properties2
typedef struct VkDisplayPlaneCapabilities2KHR {
VkStructureType sType;
void* pNext;
VkDisplayPlaneCapabilitiesKHR capabilities;
} VkDisplayPlaneCapabilities2KHR;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
capabilitiesis a VkDisplayPlaneCapabilitiesKHR structure.
34.3.2. Display Control
To set the power state of a display, call:
// Provided by VK_EXT_display_control
VkResult vkDisplayPowerControlEXT(
VkDevice device,
VkDisplayKHR display,
const VkDisplayPowerInfoEXT* pDisplayPowerInfo);-
deviceis a logical device associated withdisplay. -
displayis the display whose power state is modified. -
pDisplayPowerInfois a pointer to a VkDisplayPowerInfoEXT structure specifying the new power state ofdisplay.
The VkDisplayPowerInfoEXT structure is defined as:
// Provided by VK_EXT_display_control
typedef struct VkDisplayPowerInfoEXT {
VkStructureType sType;
const void* pNext;
VkDisplayPowerStateEXT powerState;
} VkDisplayPowerInfoEXT;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
powerStateis a VkDisplayPowerStateEXT value specifying the new power state of the display.
Possible values of VkDisplayPowerInfoEXT::powerState, specifying
the new power state of a display, are:
// Provided by VK_EXT_display_control
typedef enum VkDisplayPowerStateEXT {
VK_DISPLAY_POWER_STATE_OFF_EXT = 0,
VK_DISPLAY_POWER_STATE_SUSPEND_EXT = 1,
VK_DISPLAY_POWER_STATE_ON_EXT = 2,
} VkDisplayPowerStateEXT;-
VK_DISPLAY_POWER_STATE_OFF_EXTspecifies that the display is powered down. -
VK_DISPLAY_POWER_STATE_SUSPEND_EXTspecifies that the display is put into a low power mode, from which it may be able to transition back toVK_DISPLAY_POWER_STATE_ON_EXTmore quickly than if it were inVK_DISPLAY_POWER_STATE_OFF_EXT. This state may be the same asVK_DISPLAY_POWER_STATE_OFF_EXT. -
VK_DISPLAY_POWER_STATE_ON_EXTspecifies that the display is powered on.
34.3.3. Display Surfaces
A complete display configuration includes a mode, one or more display planes
and any parameters describing their behavior, and parameters describing some
aspects of the images associated with those planes.
Display surfaces describe the configuration of a single plane within a
complete display configuration.
To create a VkSurfaceKHR object for a display plane, call:
// Provided by VK_KHR_display
VkResult vkCreateDisplayPlaneSurfaceKHR(
VkInstance instance,
const VkDisplaySurfaceCreateInfoKHR* pCreateInfo,
const VkAllocationCallbacks* pAllocator,
VkSurfaceKHR* pSurface);-
instanceis the instance corresponding to the physical device the targeted display is on. -
pCreateInfois a pointer to a VkDisplaySurfaceCreateInfoKHR structure specifying which mode, plane, and other parameters to use, as described below. -
pAllocatoris the allocator used for host memory allocated for the surface object when there is no more specific allocator available (see Memory Allocation). -
pSurfaceis a pointer to a VkSurfaceKHR handle in which the created surface is returned.
The VkDisplaySurfaceCreateInfoKHR structure is defined as:
// Provided by VK_KHR_display
typedef struct VkDisplaySurfaceCreateInfoKHR {
VkStructureType sType;
const void* pNext;
VkDisplaySurfaceCreateFlagsKHR flags;
VkDisplayModeKHR displayMode;
uint32_t planeIndex;
uint32_t planeStackIndex;
VkSurfaceTransformFlagBitsKHR transform;
float globalAlpha;
VkDisplayPlaneAlphaFlagBitsKHR alphaMode;
VkExtent2D imageExtent;
} VkDisplaySurfaceCreateInfoKHR;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
flagsis reserved for future use, and must be zero. -
displayModeis a VkDisplayModeKHR handle specifying the mode to use when displaying this surface. -
planeIndexis the plane on which this surface appears. -
planeStackIndexis the z-order of the plane. -
transformis a VkSurfaceTransformFlagBitsKHR value specifying the transformation to apply to images as part of the scanout operation. -
globalAlphais the global alpha value. This value is ignored ifalphaModeis notVK_DISPLAY_PLANE_ALPHA_GLOBAL_BIT_KHR. -
alphaModeis a VkDisplayPlaneAlphaFlagBitsKHR value specifying the type of alpha blending to use. -
imageExtentis the size of the presentable images to use with the surface.
|
Note
Creating a display surface must not modify the state of the displays, planes, or other resources it names. For example, it must not apply the specified mode to be set on the associated display. Application of display configuration occurs as a side effect of presenting to a display surface. |
// Provided by VK_KHR_display
typedef VkFlags VkDisplaySurfaceCreateFlagsKHR;VkDisplaySurfaceCreateFlagsKHR is a bitmask type for setting a mask,
but is currently reserved for future use.
Bits which can be set in
VkDisplaySurfaceCreateInfoKHR::alphaMode, specifying the type of
alpha blending to use on a display, are:
// Provided by VK_KHR_display
typedef enum VkDisplayPlaneAlphaFlagBitsKHR {
VK_DISPLAY_PLANE_ALPHA_OPAQUE_BIT_KHR = 0x00000001,
VK_DISPLAY_PLANE_ALPHA_GLOBAL_BIT_KHR = 0x00000002,
VK_DISPLAY_PLANE_ALPHA_PER_PIXEL_BIT_KHR = 0x00000004,
VK_DISPLAY_PLANE_ALPHA_PER_PIXEL_PREMULTIPLIED_BIT_KHR = 0x00000008,
} VkDisplayPlaneAlphaFlagBitsKHR;-
VK_DISPLAY_PLANE_ALPHA_OPAQUE_BIT_KHRspecifies that the source image will be treated as opaque. -
VK_DISPLAY_PLANE_ALPHA_GLOBAL_BIT_KHRspecifies that a global alpha value must be specified that will be applied to all pixels in the source image. -
VK_DISPLAY_PLANE_ALPHA_PER_PIXEL_BIT_KHRspecifies that the alpha value will be determined by the alpha component of the source image’s pixels. If the source format contains no alpha values, no blending will be applied. The source alpha values are not premultiplied into the source image’s other color components. -
VK_DISPLAY_PLANE_ALPHA_PER_PIXEL_PREMULTIPLIED_BIT_KHRis equivalent toVK_DISPLAY_PLANE_ALPHA_PER_PIXEL_BIT_KHR, except the source alpha values are assumed to be premultiplied into the source image’s other color components.
// Provided by VK_KHR_display
typedef VkFlags VkDisplayPlaneAlphaFlagsKHR;VkDisplayPlaneAlphaFlagsKHR is a bitmask type for setting a mask of
zero or more VkDisplayPlaneAlphaFlagBitsKHR.
34.3.4. Presenting to headless surfaces
Vulkan rendering can be presented to a headless surface, where the presentation operation is a no-op producing no externally-visible result.
|
Note
Because there is no real presentation target, the headless presentation engine may be extended to impose an arbitrary or customisable set of restrictions and features. This makes it a useful portable test target for applications targeting a wide range of presentation engines where the actual target presentation engines might be scarce, unavailable or otherwise undesirable or inconvenient to use for general Vulkan application development. The usual surface query mechanisms must be used to determine the actual restrictions and features of the implementation. |
To create a headless VkSurfaceKHR object, call:
// Provided by VK_EXT_headless_surface
VkResult vkCreateHeadlessSurfaceEXT(
VkInstance instance,
const VkHeadlessSurfaceCreateInfoEXT* pCreateInfo,
const VkAllocationCallbacks* pAllocator,
VkSurfaceKHR* pSurface);-
instanceis the instance to associate the surface with. -
pCreateInfois a pointer to a VkHeadlessSurfaceCreateInfoEXT structure containing parameters affecting the creation of the surface object. -
pAllocatoris the allocator used for host memory allocated for the surface object when there is no more specific allocator available (see Memory Allocation). -
pSurfaceis a pointer to aVkSurfaceKHRhandle in which the created surface object is returned.
The VkHeadlessSurfaceCreateInfoEXT structure is defined as:
// Provided by VK_EXT_headless_surface
typedef struct VkHeadlessSurfaceCreateInfoEXT {
VkStructureType sType;
const void* pNext;
VkHeadlessSurfaceCreateFlagsEXT flags;
} VkHeadlessSurfaceCreateInfoEXT;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
flagsis reserved for future use.
For headless surfaces, currentExtent is the reserved value
(0xFFFFFFFF, 0xFFFFFFFF).
Whatever the application sets a swapchain’s imageExtent to will be the
size of the surface, after the first image is presented.
// Provided by VK_EXT_headless_surface
typedef VkFlags VkHeadlessSurfaceCreateFlagsEXT;VkHeadlessSurfaceCreateFlagsEXT is a bitmask type for setting a mask,
but is currently reserved for future use.
34.4. Querying for WSI Support
Not all physical devices will include WSI support. Within a physical device, not all queue families will support presentation. WSI support and compatibility can be determined in a platform-neutral manner (which determines support for presentation to a particular surface object) and additionally may be determined in platform-specific manners (which determine support for presentation on the specified physical device but do not guarantee support for presentation to a particular surface object).
To determine whether a queue family of a physical device supports presentation to a given surface, call:
// Provided by VK_KHR_surface
VkResult vkGetPhysicalDeviceSurfaceSupportKHR(
VkPhysicalDevice physicalDevice,
uint32_t queueFamilyIndex,
VkSurfaceKHR surface,
VkBool32* pSupported);-
physicalDeviceis the physical device. -
queueFamilyIndexis the queue family. -
surfaceis the surface. -
pSupportedis a pointer to a VkBool32, which is set toVK_TRUEto indicate support, andVK_FALSEotherwise.
34.4.1. Android Platform
On Android, all physical devices and queue families must be capable of presentation with any native window. As a result there is no Android-specific query for these capabilities.
34.4.2. Wayland Platform
To determine whether a queue family of a physical device supports presentation to a Wayland compositor, call:
// Provided by VK_KHR_wayland_surface
VkBool32 vkGetPhysicalDeviceWaylandPresentationSupportKHR(
VkPhysicalDevice physicalDevice,
uint32_t queueFamilyIndex,
struct wl_display* display);-
physicalDeviceis the physical device. -
queueFamilyIndexis the queue family index. -
displayis a pointer to thewl_displayassociated with a Wayland compositor.
This platform-specific function can be called prior to creating a surface.
34.4.3. Win32 Platform
To determine whether a queue family of a physical device supports presentation to the Microsoft Windows desktop, call:
// Provided by VK_KHR_win32_surface
VkBool32 vkGetPhysicalDeviceWin32PresentationSupportKHR(
VkPhysicalDevice physicalDevice,
uint32_t queueFamilyIndex);-
physicalDeviceis the physical device. -
queueFamilyIndexis the queue family index.
This platform-specific function can be called prior to creating a surface.
34.4.4. XCB Platform
To determine whether a queue family of a physical device supports presentation to an X11 server, using the XCB client-side library, call:
// Provided by VK_KHR_xcb_surface
VkBool32 vkGetPhysicalDeviceXcbPresentationSupportKHR(
VkPhysicalDevice physicalDevice,
uint32_t queueFamilyIndex,
xcb_connection_t* connection,
xcb_visualid_t visual_id);-
physicalDeviceis the physical device. -
queueFamilyIndexis the queue family index. -
connectionis a pointer to anxcb_connection_tto the X server. -
visual_idis an X11 visual (xcb_visualid_t).
This platform-specific function can be called prior to creating a surface.
34.4.5. Xlib Platform
To determine whether a queue family of a physical device supports presentation to an X11 server, using the Xlib client-side library, call:
// Provided by VK_KHR_xlib_surface
VkBool32 vkGetPhysicalDeviceXlibPresentationSupportKHR(
VkPhysicalDevice physicalDevice,
uint32_t queueFamilyIndex,
Display* dpy,
VisualID visualID);-
physicalDeviceis the physical device. -
queueFamilyIndexis the queue family index. -
dpyis a pointer to an XlibDisplayconnection to the server. -
visualIdis an X11 visual (VisualID).
This platform-specific function can be called prior to creating a surface.
34.4.6. DirectFB Platform
To determine whether a queue family of a physical device supports presentation with DirectFB library, call:
// Provided by VK_EXT_directfb_surface
VkBool32 vkGetPhysicalDeviceDirectFBPresentationSupportEXT(
VkPhysicalDevice physicalDevice,
uint32_t queueFamilyIndex,
IDirectFB* dfb);-
physicalDeviceis the physical device. -
queueFamilyIndexis the queue family index. -
dfbis a pointer to theIDirectFBmain interface of DirectFB.
This platform-specific function can be called prior to creating a surface.
34.4.7. Fuchsia Platform
On Fuchsia, all physical devices and queue families must be capable of presentation with any ImagePipe. As a result there is no Fuchsia-specific query for these capabilities.
34.4.8. Google Games Platform
On Google Games Platform, all physical devices and queue families with the
VK_QUEUE_GRAPHICS_BIT or VK_QUEUE_COMPUTE_BIT capabilities must
be capable of presentation with any Google Games Platform stream descriptor.
As a result, there is no query specific to Google Games Platform for these
capabilities.
34.4.9. iOS Platform
On iOS, all physical devices and queue families must be capable of presentation with any layer. As a result there is no iOS-specific query for these capabilities.
34.4.10. macOS Platform
On macOS, all physical devices and queue families must be capable of presentation with any layer. As a result there is no macOS-specific query for these capabilities.
34.4.11. VI Platform
On VI, all physical devices and queue families must be capable of presentation with any layer. As a result there is no VI-specific query for these capabilities.
34.4.12. QNX Screen Platform
To determine whether a queue family of a physical device supports presentation to a QNX Screen compositor, call:
// Provided by VK_QNX_screen_surface
VkBool32 vkGetPhysicalDeviceScreenPresentationSupportQNX(
VkPhysicalDevice physicalDevice,
uint32_t queueFamilyIndex,
struct _screen_window* window);-
physicalDeviceis the physical device. -
queueFamilyIndexis the queue family index. -
windowis the QNX Screenwindowobject.
This platform-specific function can be called prior to creating a surface.
34.5. Surface Queries
The capabilities of a swapchain targeting a surface are the intersection of the capabilities of the WSI platform, the native window or display, and the physical device. The resulting capabilities can be obtained with the queries listed below in this section.
|
Note
In addition to the surface capabilities as obtained by surface queries below, swapchain images are also subject to ordinary image creation limits as reported by vkGetPhysicalDeviceImageFormatProperties. As an application is instructed by the appropriate Valid Usage sections, both the surface capabilities and the image creation limits have to be satisfied whenever swapchain images are created. |
34.5.1. Surface Capabilities
To query the basic capabilities of a surface, needed in order to create a swapchain, call:
// Provided by VK_KHR_surface
VkResult vkGetPhysicalDeviceSurfaceCapabilitiesKHR(
VkPhysicalDevice physicalDevice,
VkSurfaceKHR surface,
VkSurfaceCapabilitiesKHR* pSurfaceCapabilities);-
physicalDeviceis the physical device that will be associated with the swapchain to be created, as described for vkCreateSwapchainKHR. -
surfaceis the surface that will be associated with the swapchain. -
pSurfaceCapabilitiesis a pointer to a VkSurfaceCapabilitiesKHR structure in which the capabilities are returned.
The VkSurfaceCapabilitiesKHR structure is defined as:
// Provided by VK_KHR_surface
typedef struct VkSurfaceCapabilitiesKHR {
uint32_t minImageCount;
uint32_t maxImageCount;
VkExtent2D currentExtent;
VkExtent2D minImageExtent;
VkExtent2D maxImageExtent;
uint32_t maxImageArrayLayers;
VkSurfaceTransformFlagsKHR supportedTransforms;
VkSurfaceTransformFlagBitsKHR currentTransform;
VkCompositeAlphaFlagsKHR supportedCompositeAlpha;
VkImageUsageFlags supportedUsageFlags;
} VkSurfaceCapabilitiesKHR;-
minImageCountis the minimum number of images the specified device supports for a swapchain created for the surface, and will be at least one. -
maxImageCountis the maximum number of images the specified device supports for a swapchain created for the surface, and will be either 0, or greater than or equal tominImageCount. A value of 0 means that there is no limit on the number of images, though there may be limits related to the total amount of memory used by presentable images. -
currentExtentis the current width and height of the surface, or the special value (0xFFFFFFFF, 0xFFFFFFFF) indicating that the surface size will be determined by the extent of a swapchain targeting the surface. -
minImageExtentcontains the smallest valid swapchain extent for the surface on the specified device. Thewidthandheightof the extent will each be less than or equal to the correspondingwidthandheightofcurrentExtent, unlesscurrentExtenthas the special value described above. -
maxImageExtentcontains the largest valid swapchain extent for the surface on the specified device. Thewidthandheightof the extent will each be greater than or equal to the correspondingwidthandheightofminImageExtent. Thewidthandheightof the extent will each be greater than or equal to the correspondingwidthandheightofcurrentExtent, unlesscurrentExtenthas the special value described above. -
maxImageArrayLayersis the maximum number of layers presentable images can have for a swapchain created for this device and surface, and will be at least one. -
supportedTransformsis a bitmask of VkSurfaceTransformFlagBitsKHR indicating the presentation transforms supported for the surface on the specified device. At least one bit will be set. -
currentTransformis VkSurfaceTransformFlagBitsKHR value indicating the surface’s current transform relative to the presentation engine’s natural orientation. -
supportedCompositeAlphais a bitmask of VkCompositeAlphaFlagBitsKHR, representing the alpha compositing modes supported by the presentation engine for the surface on the specified device, and at least one bit will be set. Opaque composition can be achieved in any alpha compositing mode by either using an image format that has no alpha component, or by ensuring that all pixels in the presentable images have an alpha value of 1.0. -
supportedUsageFlagsis a bitmask of VkImageUsageFlagBits representing the ways the application can use the presentable images of a swapchain created with VkPresentModeKHR set toVK_PRESENT_MODE_IMMEDIATE_KHR,VK_PRESENT_MODE_MAILBOX_KHR,VK_PRESENT_MODE_FIFO_KHRorVK_PRESENT_MODE_FIFO_RELAXED_KHRfor the surface on the specified device.VK_IMAGE_USAGE_COLOR_ATTACHMENT_BITmust be included in the set. Implementations may support additional usages.
|
Note
Supported usage flags of a presentable image when using
|
|
Note
Formulas such as min(N, |
To query the basic capabilities of a surface defined by the core or extensions, call:
// Provided by VK_KHR_get_surface_capabilities2
VkResult vkGetPhysicalDeviceSurfaceCapabilities2KHR(
VkPhysicalDevice physicalDevice,
const VkPhysicalDeviceSurfaceInfo2KHR* pSurfaceInfo,
VkSurfaceCapabilities2KHR* pSurfaceCapabilities);-
physicalDeviceis the physical device that will be associated with the swapchain to be created, as described for vkCreateSwapchainKHR. -
pSurfaceInfois a pointer to a VkPhysicalDeviceSurfaceInfo2KHR structure describing the surface and other fixed parameters that would be consumed by vkCreateSwapchainKHR. -
pSurfaceCapabilitiesis a pointer to a VkSurfaceCapabilities2KHR structure in which the capabilities are returned.
vkGetPhysicalDeviceSurfaceCapabilities2KHR behaves similarly to
vkGetPhysicalDeviceSurfaceCapabilitiesKHR, with the ability to specify
extended inputs via chained input structures, and to return extended
information via chained output structures.
The VkPhysicalDeviceSurfaceInfo2KHR structure is defined as:
// Provided by VK_KHR_get_surface_capabilities2
typedef struct VkPhysicalDeviceSurfaceInfo2KHR {
VkStructureType sType;
const void* pNext;
VkSurfaceKHR surface;
} VkPhysicalDeviceSurfaceInfo2KHR;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
surfaceis the surface that will be associated with the swapchain.
The members of VkPhysicalDeviceSurfaceInfo2KHR correspond to the
arguments to vkGetPhysicalDeviceSurfaceCapabilitiesKHR, with
sType and pNext added for extensibility.
Additional capabilities of a surface may be available to swapchains created
with different full-screen exclusive settings - particularly if exclusive
full-screen access is application controlled.
These additional capabilities can be queried by adding a
VkSurfaceFullScreenExclusiveInfoEXT structure to the pNext chain
of this structure when used to query surface properties.
Additionally, for Win32 surfaces with application controlled exclusive
full-screen access, chaining a
VkSurfaceFullScreenExclusiveWin32InfoEXT structure may also report
additional surface capabilities.
These additional capabilities only apply to swapchains created with the same
parameters included in the pNext chain of
VkSwapchainCreateInfoKHR.
If the pNext chain of VkSwapchainCreateInfoKHR includes a
VkSurfaceFullScreenExclusiveInfoEXT structure, then that structure
specifies the application’s preferred full-screen transition behavior.
The VkSurfaceFullScreenExclusiveInfoEXT structure is defined as:
// Provided by VK_EXT_full_screen_exclusive
typedef struct VkSurfaceFullScreenExclusiveInfoEXT {
VkStructureType sType;
void* pNext;
VkFullScreenExclusiveEXT fullScreenExclusive;
} VkSurfaceFullScreenExclusiveInfoEXT;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
fullScreenExclusiveis a VkFullScreenExclusiveEXT value specifying the preferred full-screen transition behavior.
If this structure is not present, fullScreenExclusive is considered to
be VK_FULL_SCREEN_EXCLUSIVE_DEFAULT_EXT.
Possible values of
VkSurfaceFullScreenExclusiveInfoEXT::fullScreenExclusive are:
// Provided by VK_EXT_full_screen_exclusive
typedef enum VkFullScreenExclusiveEXT {
VK_FULL_SCREEN_EXCLUSIVE_DEFAULT_EXT = 0,
VK_FULL_SCREEN_EXCLUSIVE_ALLOWED_EXT = 1,
VK_FULL_SCREEN_EXCLUSIVE_DISALLOWED_EXT = 2,
VK_FULL_SCREEN_EXCLUSIVE_APPLICATION_CONTROLLED_EXT = 3,
} VkFullScreenExclusiveEXT;-
VK_FULL_SCREEN_EXCLUSIVE_DEFAULT_EXTindicates the implementation should determine the appropriate full-screen method by whatever means it deems appropriate. -
VK_FULL_SCREEN_EXCLUSIVE_ALLOWED_EXTindicates the implementation may use full-screen exclusive mechanisms when available. Such mechanisms may result in better performance and/or the availability of different presentation capabilities, but may require a more disruptive transition during swapchain initialization, first presentation and/or destruction. -
VK_FULL_SCREEN_EXCLUSIVE_DISALLOWED_EXTindicates the implementation should avoid using full-screen mechanisms which rely on disruptive transitions. -
VK_FULL_SCREEN_EXCLUSIVE_APPLICATION_CONTROLLED_EXTindicates the application will manage full-screen exclusive mode by using the vkAcquireFullScreenExclusiveModeEXT and vkReleaseFullScreenExclusiveModeEXT commands.
The VkSurfaceFullScreenExclusiveWin32InfoEXT structure is defined as:
// Provided by VK_KHR_win32_surface with VK_EXT_full_screen_exclusive
typedef struct VkSurfaceFullScreenExclusiveWin32InfoEXT {
VkStructureType sType;
const void* pNext;
HMONITOR hmonitor;
} VkSurfaceFullScreenExclusiveWin32InfoEXT;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
hmonitoris the Win32HMONITORhandle identifying the display to create the surface with.
|
Note
If |
|
Note
It is the responsibility of the application to change the display settings of the targeted Win32 display using the appropriate platform APIs. Such changes may alter the surface capabilities reported for the created surface. |
The VkSurfaceCapabilities2KHR structure is defined as:
// Provided by VK_KHR_get_surface_capabilities2
typedef struct VkSurfaceCapabilities2KHR {
VkStructureType sType;
void* pNext;
VkSurfaceCapabilitiesKHR surfaceCapabilities;
} VkSurfaceCapabilities2KHR;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
surfaceCapabilitiesis a VkSurfaceCapabilitiesKHR structure describing the capabilities of the specified surface.
If the VK_GOOGLE_surfaceless_query extension is enabled and
VkPhysicalDeviceSurfaceInfo2KHR::surface in the
vkGetPhysicalDeviceSurfaceCapabilities2KHR call is
VK_NULL_HANDLE, the values returned in minImageCount,
maxImageCount, currentExtent, and currentTransform will
not reflect that of any surface and will instead be as such:
-
minImageCountandmaxImageCountwill be 0xFFFFFFFF -
currentExtentwill be (0xFFFFFFFF, 0xFFFFFFFF) -
currentTransformwill beVK_SURFACE_TRANSFORM_INHERIT_BIT_KHR
An application queries if a protected VkSurfaceKHR is displayable on a
specific windowing system using VkSurfaceProtectedCapabilitiesKHR,
which can be passed in pNext parameter of
VkSurfaceCapabilities2KHR.
The VkSurfaceProtectedCapabilitiesKHR structure is defined as:
// Provided by VK_KHR_surface_protected_capabilities
typedef struct VkSurfaceProtectedCapabilitiesKHR {
VkStructureType sType;
const void* pNext;
VkBool32 supportsProtected;
} VkSurfaceProtectedCapabilitiesKHR;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
supportsProtectedspecifies whether a protected swapchain created from VkPhysicalDeviceSurfaceInfo2KHR::surfacefor a particular windowing system can be displayed on screen or not. IfsupportsProtectedisVK_TRUE, then creation of swapchains with theVK_SWAPCHAIN_CREATE_PROTECTED_BIT_KHRflag set must be supported forsurface.
If the VK_GOOGLE_surfaceless_query extension is enabled, the value
returned in supportsProtected will be identical for every valid
surface created on this physical device, and so in the
vkGetPhysicalDeviceSurfaceCapabilities2KHR call,
VkPhysicalDeviceSurfaceInfo2KHR::surface can be
VK_NULL_HANDLE.
In that case, the contents of
VkSurfaceCapabilities2KHR::surfaceCapabilities as well as any
other struct chained to it will be undefined.
The VkSurfacePresentScalingCapabilitiesEXT structure is defined as:
// Provided by VK_EXT_surface_maintenance1
typedef struct VkSurfacePresentScalingCapabilitiesEXT {
VkStructureType sType;
void* pNext;
VkPresentScalingFlagsEXT supportedPresentScaling;
VkPresentGravityFlagsEXT supportedPresentGravityX;
VkPresentGravityFlagsEXT supportedPresentGravityY;
VkExtent2D minScaledImageExtent;
VkExtent2D maxScaledImageExtent;
} VkSurfacePresentScalingCapabilitiesEXT;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
supportedPresentScalingis a bitmask of VkPresentScalingFlagBitsEXT representing the scaling methods supported by the surface, or0if application-defined scaling is not supported. -
supportedPresentGravityXis a bitmask of VkPresentGravityFlagBitsEXT representing the X-axis pixel gravity supported by the surface, or0if Vulkan-defined pixel gravity is not supported for the X axis. -
supportedPresentGravityYis a bitmask of VkPresentGravityFlagBitsEXT representing the Y-axis pixel gravity supported by the surface, or0if Vulkan-defined pixel gravity is not supported for the Y axis. -
minScaledImageExtentcontains the smallest valid swapchain extent for the surface on the specified device when one of the scaling methods specified insupportedPresentScalingis used, or the special value (0xFFFFFFFF, 0xFFFFFFFF) indicating that the surface size will be determined by the extent of a swapchain targeting the surface. Thewidthandheightof the extent will each be smaller than or equal to the correspondingwidthandheightof VkSurfaceCapabilitiesKHR::minImageExtent. -
maxScaledImageExtentcontains the largest valid swapchain extent for the surface on the specified device when one of the scaling methods specified insupportedPresentScalingis used, or the special value described above forminScaledImageExtent. Thewidthandheightof the extent will each be greater than or equal to the correspondingwidthandheightof VkSurfaceCapabilitiesKHR::maxImageExtent.
Before creating a swapchain whose scaling mode can be specified through the
use of VkSwapchainPresentScalingCreateInfoEXT, obtain the set of
supported scaling modes by including a VkSurfacePresentModeEXT
structure in the pNext chain of VkPhysicalDeviceSurfaceInfo2KHR
when calling vkGetPhysicalDeviceSurfaceCapabilities2KHR.
The implementation must return the same values in
VkSurfacePresentScalingCapabilitiesEXT for any of the compatible
present modes as obtained through
VkSurfacePresentModeCompatibilityEXT.
Bits which may be set in
VkSurfacePresentScalingCapabilitiesEXT::supportedPresentScaling,
specifying scaling modes supported by the surface, are:
// Provided by VK_EXT_surface_maintenance1
typedef enum VkPresentScalingFlagBitsEXT {
VK_PRESENT_SCALING_ONE_TO_ONE_BIT_EXT = 0x00000001,
VK_PRESENT_SCALING_ASPECT_RATIO_STRETCH_BIT_EXT = 0x00000002,
VK_PRESENT_SCALING_STRETCH_BIT_EXT = 0x00000004,
} VkPresentScalingFlagBitsEXT;-
VK_PRESENT_SCALING_ONE_TO_ONE_BIT_EXTspecifies that no scaling occurs, and pixels in the swapchain image are mapped to one and only one pixel in the surface. The mapping between pixels is defined by the chosen presentation gravity. -
VK_PRESENT_SCALING_ASPECT_RATIO_STRETCH_BIT_EXTspecifies that the swapchain image will be minified or magnified such that at least one of the resulting width or height is equal to the corresponding surface dimension, and the other resulting dimension is less than or equal to the corresponding surface dimension, with the aspect ratio of the resulting image being identical to that of the original swapchain image. -
VK_PRESENT_SCALING_STRETCH_BIT_EXTspecifies that the swapchain image will be minified or magnified such that the resulting image dimensions are equal to those of the surface.
// Provided by VK_EXT_surface_maintenance1
typedef VkFlags VkPresentScalingFlagsEXT;VkPresentScalingFlagsEXT is a bitmask type for setting a mask of zero
or more VkPresentScalingFlagBitsEXT.
Bits which may be set in the
VkSurfacePresentScalingCapabilitiesEXT::supportedPresentGravityX
or supportedPresentGravityY fields, specifying the gravity of
presented pixels supported by the surface, are:
// Provided by VK_EXT_surface_maintenance1
typedef enum VkPresentGravityFlagBitsEXT {
VK_PRESENT_GRAVITY_MIN_BIT_EXT = 0x00000001,
VK_PRESENT_GRAVITY_MAX_BIT_EXT = 0x00000002,
VK_PRESENT_GRAVITY_CENTERED_BIT_EXT = 0x00000004,
} VkPresentGravityFlagBitsEXT;-
VK_PRESENT_GRAVITY_MIN_BIT_EXTmeans that the pixels will gravitate towards the top or left side of the surface. -
VK_PRESENT_GRAVITY_MAX_BIT_EXTmeans that the pixels will gravitate towards the bottom or right side of the surface. -
VK_PRESENT_GRAVITY_CENTERED_BIT_EXTmeans that the pixels will be centered in the surface.
If the value in VkSurfaceCapabilitiesKHR::currentTransform is
not VK_SURFACE_TRANSFORM_IDENTITY_BIT_KHR, it is
implementation-defined whether the gravity configuration applies to the
presented image before or after transformation.
// Provided by VK_EXT_surface_maintenance1
typedef VkFlags VkPresentGravityFlagsEXT;VkPresentGravityFlagsEXT is a bitmask type for setting a mask of zero
or more VkPresentGravityFlagBitsEXT.
The VkSurfacePresentModeEXT structure is defined as:
// Provided by VK_EXT_surface_maintenance1
typedef struct VkSurfacePresentModeEXT {
VkStructureType sType;
void* pNext;
VkPresentModeKHR presentMode;
} VkSurfacePresentModeEXT;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
presentModeis the presentation mode the swapchain will use.
If the VkSurfacePresentModeEXT structure is included in the
pNext chain of VkPhysicalDeviceSurfaceInfo2KHR, the values
returned in VkSurfaceCapabilitiesKHR::minImageCount,
VkSurfaceCapabilitiesKHR::maxImageCount,
VkSurfacePresentScalingCapabilitiesEXT::minScaledImageExtent,
and VkSurfacePresentScalingCapabilitiesEXT::maxScaledImageExtent
are valid only for the specified presentMode.
If presentMode is VK_PRESENT_MODE_SHARED_DEMAND_REFRESH_KHR or
VK_PRESENT_MODE_SHARED_CONTINUOUS_REFRESH_KHR, the per-present mode
image counts must both be one.
The per-present mode image counts may be less-than or greater-than the
image counts returned when VkSurfacePresentModeEXT is not provided.
|
Note
If VkSwapchainPresentModesCreateInfoEXT is provided to swapchain
creation, the requirements for forward progress may be less strict.
For example, a FIFO swapchain might only require 2 images to guarantee
forward progress, but a MAILBOX one might require 4.
Without the per-present image counts, such an implementation would have to
return 4 in VkSurfaceCapabilitiesKHR:: VkSwapchainPresentModesCreateInfoEXT is required for the specification to be backwards compatible with applications that do not know about, or make use of this feature. |
The VkSurfacePresentModeCompatibilityEXT structure is defined as:
// Provided by VK_EXT_surface_maintenance1
typedef struct VkSurfacePresentModeCompatibilityEXT {
VkStructureType sType;
void* pNext;
uint32_t presentModeCount;
VkPresentModeKHR* pPresentModes;
} VkSurfacePresentModeCompatibilityEXT;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
presentModeCountis an integer related to the number of present modes available or queried, as described below. -
pPresentModesis a pointer to an array of VkPresentModeKHR in which present modes compatible with a given present mode are returned.
If pPresentModes is NULL, then the number of present modes that are
compatible with the one specified in VkSurfacePresentModeEXT is
returned in presentModeCount.
Otherwise, presentModeCount must be set by the user to the number of
elements in the pPresentModes array, and on return the variable is
overwritten with the number of values actually written to
pPresentModes.
If the value of presentModeCount is less than the number of compatible
present modes that are supported, at most presentModeCount values will
be written to pPresentModes.
The implementation must include the present mode passed to
VkSurfacePresentModeEXT in pPresentModes, unless
presentModeCount is zero.
Before creating a swapchain whose present modes can be modified through the
use of VkSwapchainPresentModesCreateInfoEXT, obtain the set of present
modes compatible with a given initial present mode by including a
VkSurfacePresentModeEXT structure in the pNext chain of
VkPhysicalDeviceSurfaceInfo2KHR when calling
vkGetPhysicalDeviceSurfaceCapabilities2KHR.
The VkSharedPresentSurfaceCapabilitiesKHR structure is defined as:
-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
sharedPresentSupportedUsageFlagsis a bitmask of VkImageUsageFlagBits representing the ways the application can use the shared presentable image from a swapchain created with VkPresentModeKHR set toVK_PRESENT_MODE_SHARED_DEMAND_REFRESH_KHRorVK_PRESENT_MODE_SHARED_CONTINUOUS_REFRESH_KHRfor the surface on the specified device.VK_IMAGE_USAGE_COLOR_ATTACHMENT_BITmust be included in the set but implementations may support additional usages.
The VkDisplayNativeHdrSurfaceCapabilitiesAMD structure is defined as:
// Provided by VK_AMD_display_native_hdr
typedef struct VkDisplayNativeHdrSurfaceCapabilitiesAMD {
VkStructureType sType;
void* pNext;
VkBool32 localDimmingSupport;
} VkDisplayNativeHdrSurfaceCapabilitiesAMD;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
localDimmingSupportspecifies whether the surface supports local dimming. If this isVK_TRUE, VkSwapchainDisplayNativeHdrCreateInfoAMD can be used to explicitly enable or disable local dimming for the surface. Local dimming may also be overridden by vkSetLocalDimmingAMD during the lifetime of the swapchain.
The VkSurfaceCapabilitiesFullScreenExclusiveEXT structure is defined
as:
// Provided by VK_EXT_full_screen_exclusive
typedef struct VkSurfaceCapabilitiesFullScreenExclusiveEXT {
VkStructureType sType;
void* pNext;
VkBool32 fullScreenExclusiveSupported;
} VkSurfaceCapabilitiesFullScreenExclusiveEXT;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
fullScreenExclusiveControlSupportedis a boolean describing whether the surface is able to make use of exclusive full-screen access.
This structure can be included in the pNext chain of
VkSurfaceCapabilities2KHR to determine support for exclusive
full-screen access.
If fullScreenExclusiveSupported is VK_FALSE, it indicates that
exclusive full-screen access is not obtainable for this surface.
Applications must not attempt to create swapchains with
VK_FULL_SCREEN_EXCLUSIVE_APPLICATION_CONTROLLED_EXT set if
fullScreenExclusiveSupported is VK_FALSE.
The VkSurfaceCapabilitiesPresentBarrierNV structure is defined as:
// Provided by VK_NV_present_barrier
typedef struct VkSurfaceCapabilitiesPresentBarrierNV {
VkStructureType sType;
void* pNext;
VkBool32 presentBarrierSupported;
} VkSurfaceCapabilitiesPresentBarrierNV;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
presentBarrierSupportedis a boolean describing whether the surface is able to make use of the present barrier feature.
This structure can be included in the pNext chain of
VkSurfaceCapabilities2KHR to determine support for present barrier
access.
If presentBarrierSupported is VK_FALSE, it indicates that the
present barrier feature is not obtainable for this surface.
The VkPresentTimingSurfaceCapabilitiesEXT structure is defined as:
// Provided by VK_EXT_present_timing
typedef struct VkPresentTimingSurfaceCapabilitiesEXT {
VkStructureType sType;
void* pNext;
VkBool32 presentTimingSupported;
VkBool32 presentAtAbsoluteTimeSupported;
VkBool32 presentAtRelativeTimeSupported;
VkPresentStageFlagsEXT presentStageQueries;
VkPresentStageFlagsEXT presentStageTargets;
} VkPresentTimingSurfaceCapabilitiesEXT;-
sTypeis the type of this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
presentTimingSupportedindicates whether querying presentation timestamps is supported for a swapchain created from VkPhysicalDeviceSurfaceInfo2KHR::surface. -
presentAtAbsoluteTimeSupportedindicates whether a swapchain created from VkPhysicalDeviceSurfaceInfo2KHR::surfacesupports presenting images with absolute times using VkPresentTimeEXT::targetPresentTime. -
presentAtRelativeTimeSupportedindicates whether a swapchain created from VkPhysicalDeviceSurfaceInfo2KHR::surfacesupports presenting images with relative times using VkPresentTimeEXT::minPresentDuration. -
presentStageQueriesis a bitmask of VkPresentStageFlagBitsEXT indicating which present stages a swapchain created from VkPhysicalDeviceSurfaceInfo2KHR::surfaceis able to provide timing information for. -
presentStageTargetsis a bitmask of VkPresentStageFlagBitsEXT indicating which present stages a swapchain created from VkPhysicalDeviceSurfaceInfo2KHR::surfaceis able to provide target present times for.
To query the basic capabilities of a surface, needed in order to create a swapchain, call:
// Provided by VK_EXT_display_surface_counter
VkResult vkGetPhysicalDeviceSurfaceCapabilities2EXT(
VkPhysicalDevice physicalDevice,
VkSurfaceKHR surface,
VkSurfaceCapabilities2EXT* pSurfaceCapabilities);-
physicalDeviceis the physical device that will be associated with the swapchain to be created, as described for vkCreateSwapchainKHR. -
surfaceis the surface that will be associated with the swapchain. -
pSurfaceCapabilitiesis a pointer to a VkSurfaceCapabilities2EXT structure in which the capabilities are returned.
vkGetPhysicalDeviceSurfaceCapabilities2EXT behaves similarly to
vkGetPhysicalDeviceSurfaceCapabilitiesKHR, with the ability to return
extended information by adding extending structures to the pNext chain
of its pSurfaceCapabilities parameter.
The VkSurfaceCapabilities2EXT structure is defined as:
// Provided by VK_EXT_display_surface_counter
typedef struct VkSurfaceCapabilities2EXT {
VkStructureType sType;
void* pNext;
uint32_t minImageCount;
uint32_t maxImageCount;
VkExtent2D currentExtent;
VkExtent2D minImageExtent;
VkExtent2D maxImageExtent;
uint32_t maxImageArrayLayers;
VkSurfaceTransformFlagsKHR supportedTransforms;
VkSurfaceTransformFlagBitsKHR currentTransform;
VkCompositeAlphaFlagsKHR supportedCompositeAlpha;
VkImageUsageFlags supportedUsageFlags;
VkSurfaceCounterFlagsEXT supportedSurfaceCounters;
} VkSurfaceCapabilities2EXT;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
minImageCountis the minimum number of images the specified device supports for a swapchain created for the surface, and will be at least one. -
maxImageCountis the maximum number of images the specified device supports for a swapchain created for the surface, and will be either 0, or greater than or equal tominImageCount. A value of 0 means that there is no limit on the number of images, though there may be limits related to the total amount of memory used by presentable images. -
currentExtentis the current width and height of the surface, or the special value (0xFFFFFFFF, 0xFFFFFFFF) indicating that the surface size will be determined by the extent of a swapchain targeting the surface. -
minImageExtentcontains the smallest valid swapchain extent for the surface on the specified device. Thewidthandheightof the extent will each be less than or equal to the correspondingwidthandheightofcurrentExtent, unlesscurrentExtenthas the special value described above. -
maxImageExtentcontains the largest valid swapchain extent for the surface on the specified device. Thewidthandheightof the extent will each be greater than or equal to the correspondingwidthandheightofminImageExtent. Thewidthandheightof the extent will each be greater than or equal to the correspondingwidthandheightofcurrentExtent, unlesscurrentExtenthas the special value described above. -
maxImageArrayLayersis the maximum number of layers presentable images can have for a swapchain created for this device and surface, and will be at least one. -
supportedTransformsis a bitmask of VkSurfaceTransformFlagBitsKHR indicating the presentation transforms supported for the surface on the specified device. At least one bit will be set. -
currentTransformis VkSurfaceTransformFlagBitsKHR value indicating the surface’s current transform relative to the presentation engine’s natural orientation. -
supportedCompositeAlphais a bitmask of VkCompositeAlphaFlagBitsKHR, representing the alpha compositing modes supported by the presentation engine for the surface on the specified device, and at least one bit will be set. Opaque composition can be achieved in any alpha compositing mode by either using an image format that has no alpha component, or by ensuring that all pixels in the presentable images have an alpha value of 1.0. -
supportedUsageFlagsis a bitmask of VkImageUsageFlagBits representing the ways the application can use the presentable images of a swapchain created with VkPresentModeKHR set toVK_PRESENT_MODE_IMMEDIATE_KHR,VK_PRESENT_MODE_MAILBOX_KHR,VK_PRESENT_MODE_FIFO_KHRorVK_PRESENT_MODE_FIFO_RELAXED_KHRfor the surface on the specified device.VK_IMAGE_USAGE_COLOR_ATTACHMENT_BITmust be included in the set. Implementations may support additional usages. -
supportedSurfaceCountersis a bitmask of VkSurfaceCounterFlagBitsEXT indicating the supported surface counter types.
Bits which can be set in
VkSurfaceCapabilities2EXT::supportedSurfaceCounters, indicating
supported surface counter types, are:
// Provided by VK_EXT_display_surface_counter
typedef enum VkSurfaceCounterFlagBitsEXT {
VK_SURFACE_COUNTER_VBLANK_BIT_EXT = 0x00000001,
VK_SURFACE_COUNTER_VBLANK_EXT = VK_SURFACE_COUNTER_VBLANK_BIT_EXT,
} VkSurfaceCounterFlagBitsEXT;-
VK_SURFACE_COUNTER_VBLANK_BIT_EXTspecifies a counter incrementing once every time a vertical blanking period occurs on the display associated with the surface.
// Provided by VK_EXT_display_surface_counter
typedef VkFlags VkSurfaceCounterFlagsEXT;VkSurfaceCounterFlagsEXT is a bitmask type for setting a mask of zero
or more VkSurfaceCounterFlagBitsEXT.
Bits which may be set in
VkSurfaceCapabilitiesKHR::supportedTransforms indicating the
presentation transforms supported for the surface on the specified device,
and possible values of
VkSurfaceCapabilitiesKHR::currentTransform indicating the
surface’s current transform relative to the presentation engine’s natural
orientation, are:
// Provided by VK_KHR_surface
typedef enum VkSurfaceTransformFlagBitsKHR {
VK_SURFACE_TRANSFORM_IDENTITY_BIT_KHR = 0x00000001,
VK_SURFACE_TRANSFORM_ROTATE_90_BIT_KHR = 0x00000002,
VK_SURFACE_TRANSFORM_ROTATE_180_BIT_KHR = 0x00000004,
VK_SURFACE_TRANSFORM_ROTATE_270_BIT_KHR = 0x00000008,
VK_SURFACE_TRANSFORM_HORIZONTAL_MIRROR_BIT_KHR = 0x00000010,
VK_SURFACE_TRANSFORM_HORIZONTAL_MIRROR_ROTATE_90_BIT_KHR = 0x00000020,
VK_SURFACE_TRANSFORM_HORIZONTAL_MIRROR_ROTATE_180_BIT_KHR = 0x00000040,
VK_SURFACE_TRANSFORM_HORIZONTAL_MIRROR_ROTATE_270_BIT_KHR = 0x00000080,
VK_SURFACE_TRANSFORM_INHERIT_BIT_KHR = 0x00000100,
} VkSurfaceTransformFlagBitsKHR;-
VK_SURFACE_TRANSFORM_IDENTITY_BIT_KHRspecifies that image content is presented without being transformed. -
VK_SURFACE_TRANSFORM_ROTATE_90_BIT_KHRspecifies that image content is rotated 90 degrees clockwise. -
VK_SURFACE_TRANSFORM_ROTATE_180_BIT_KHRspecifies that image content is rotated 180 degrees clockwise. -
VK_SURFACE_TRANSFORM_ROTATE_270_BIT_KHRspecifies that image content is rotated 270 degrees clockwise. -
VK_SURFACE_TRANSFORM_HORIZONTAL_MIRROR_BIT_KHRspecifies that image content is mirrored horizontally. -
VK_SURFACE_TRANSFORM_HORIZONTAL_MIRROR_ROTATE_90_BIT_KHRspecifies that image content is mirrored horizontally, then rotated 90 degrees clockwise. -
VK_SURFACE_TRANSFORM_HORIZONTAL_MIRROR_ROTATE_180_BIT_KHRspecifies that image content is mirrored horizontally, then rotated 180 degrees clockwise. -
VK_SURFACE_TRANSFORM_HORIZONTAL_MIRROR_ROTATE_270_BIT_KHRspecifies that image content is mirrored horizontally, then rotated 270 degrees clockwise. -
VK_SURFACE_TRANSFORM_INHERIT_BIT_KHRspecifies that the presentation transform is not specified, and is instead determined by platform-specific considerations and mechanisms outside Vulkan.
// Provided by VK_KHR_display
typedef VkFlags VkSurfaceTransformFlagsKHR;VkSurfaceTransformFlagsKHR is a bitmask type for setting a mask of
zero or more VkSurfaceTransformFlagBitsKHR.
The supportedCompositeAlpha member is of type
VkCompositeAlphaFlagBitsKHR, containing the following values:
// Provided by VK_KHR_surface
typedef enum VkCompositeAlphaFlagBitsKHR {
VK_COMPOSITE_ALPHA_OPAQUE_BIT_KHR = 0x00000001,
VK_COMPOSITE_ALPHA_PRE_MULTIPLIED_BIT_KHR = 0x00000002,
VK_COMPOSITE_ALPHA_POST_MULTIPLIED_BIT_KHR = 0x00000004,
VK_COMPOSITE_ALPHA_INHERIT_BIT_KHR = 0x00000008,
} VkCompositeAlphaFlagBitsKHR;These values are described as follows:
-
VK_COMPOSITE_ALPHA_OPAQUE_BIT_KHR: The alpha component, if it exists, of the images is ignored in the compositing process. Instead, the image is treated as if it has a constant alpha of 1.0. -
VK_COMPOSITE_ALPHA_PRE_MULTIPLIED_BIT_KHR: The alpha component, if it exists, of the images is respected in the compositing process. The non-alpha components of the image are expected to already be multiplied by the alpha component by the application. -
VK_COMPOSITE_ALPHA_POST_MULTIPLIED_BIT_KHR: The alpha component, if it exists, of the images is respected in the compositing process. The non-alpha components of the image are not expected to already be multiplied by the alpha component by the application; instead, the compositor will multiply the non-alpha components of the image by the alpha component during compositing. -
VK_COMPOSITE_ALPHA_INHERIT_BIT_KHR: The way in which the presentation engine treats the alpha component in the images is unknown to the Vulkan API. Instead, the application is responsible for setting the composite alpha blending mode using native window system commands. If the application does not set the blending mode using native window system commands, then a platform-specific default will be used.
// Provided by VK_KHR_surface
typedef VkFlags VkCompositeAlphaFlagsKHR;VkCompositeAlphaFlagsKHR is a bitmask type for setting a mask of zero
or more VkCompositeAlphaFlagBitsKHR.
34.5.2. Surface Format Support
To query the supported swapchain format-color space pairs for a surface, call:
// Provided by VK_KHR_surface
VkResult vkGetPhysicalDeviceSurfaceFormatsKHR(
VkPhysicalDevice physicalDevice,
VkSurfaceKHR surface,
uint32_t* pSurfaceFormatCount,
VkSurfaceFormatKHR* pSurfaceFormats);-
physicalDeviceis the physical device that will be associated with the swapchain to be created, as described for vkCreateSwapchainKHR. -
surfaceis the surface that will be associated with the swapchain. -
pSurfaceFormatCountis a pointer to an integer related to the number of format pairs available or queried, as described below. -
pSurfaceFormatsis eitherNULLor a pointer to an array ofVkSurfaceFormatKHRstructures.
If pSurfaceFormats is NULL, then the number of format pairs
supported for the given surface is returned in
pSurfaceFormatCount.
Otherwise, pSurfaceFormatCount must point to a variable set by the
user to the number of elements in the pSurfaceFormats array, and on
return the variable is overwritten with the number of structures actually
written to pSurfaceFormats.
If the value of pSurfaceFormatCount is less than the number of format
pairs supported, at most pSurfaceFormatCount structures will be
written, and VK_INCOMPLETE will be returned instead of
VK_SUCCESS, to indicate that not all the available format pairs were
returned.
The number of format pairs supported must be greater than or equal to 1.
pSurfaceFormats must not contain an entry whose value for
format is VK_FORMAT_UNDEFINED.
If pSurfaceFormats includes an entry whose value for colorSpace
is VK_COLOR_SPACE_SRGB_NONLINEAR_KHR and whose value for format
is a UNORM (or SRGB) format and the corresponding SRGB (or UNORM) format is
a color renderable format for VK_IMAGE_TILING_OPTIMAL, then
pSurfaceFormats must also contain an entry with the same value for
colorSpace and format equal to the corresponding SRGB (or UNORM)
format.
If the VK_GOOGLE_surfaceless_query extension is enabled, the values
returned in pSurfaceFormats will be identical for every valid surface
created on this physical device, and so surface can be
VK_NULL_HANDLE.
The VkSurfaceFormatKHR structure is defined as:
// Provided by VK_KHR_surface
typedef struct VkSurfaceFormatKHR {
VkFormat format;
VkColorSpaceKHR colorSpace;
} VkSurfaceFormatKHR;-
formatis a VkFormat that is compatible with the specified surface. -
colorSpaceis a presentation VkColorSpaceKHR that is compatible with the surface.
To query the supported swapchain format tuples for a surface, call:
// Provided by VK_KHR_get_surface_capabilities2
VkResult vkGetPhysicalDeviceSurfaceFormats2KHR(
VkPhysicalDevice physicalDevice,
const VkPhysicalDeviceSurfaceInfo2KHR* pSurfaceInfo,
uint32_t* pSurfaceFormatCount,
VkSurfaceFormat2KHR* pSurfaceFormats);-
physicalDeviceis the physical device that will be associated with the swapchain to be created, as described for vkCreateSwapchainKHR. -
pSurfaceInfois a pointer to a VkPhysicalDeviceSurfaceInfo2KHR structure describing the surface and other fixed parameters that would be consumed by vkCreateSwapchainKHR. -
pSurfaceFormatCountis a pointer to an integer related to the number of format tuples available or queried, as described below. -
pSurfaceFormatsis eitherNULLor a pointer to an array of VkSurfaceFormat2KHR structures.
vkGetPhysicalDeviceSurfaceFormats2KHR behaves similarly to
vkGetPhysicalDeviceSurfaceFormatsKHR, with the ability to be extended
via pNext chains.
If pSurfaceFormats is NULL, then the number of format tuples
supported for the given surface is returned in
pSurfaceFormatCount.
Otherwise, pSurfaceFormatCount must point to a variable set by the
user to the number of elements in the pSurfaceFormats array, and on
return the variable is overwritten with the number of structures actually
written to pSurfaceFormats.
If the value of pSurfaceFormatCount is less than the number of format
tuples supported, at most pSurfaceFormatCount structures will be
written, and VK_INCOMPLETE will be returned instead of
VK_SUCCESS, to indicate that not all the available values were
returned.
The VkSurfaceFormat2KHR structure is defined as:
// Provided by VK_KHR_get_surface_capabilities2
typedef struct VkSurfaceFormat2KHR {
VkStructureType sType;
void* pNext;
VkSurfaceFormatKHR surfaceFormat;
} VkSurfaceFormat2KHR;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
surfaceFormatis a VkSurfaceFormatKHR structure describing a format-color space pair that is compatible with the specified surface.
If the imageCompressionControlSwapchain feature is supported and a
VkImageCompressionPropertiesEXT structure is included in the
pNext chain of this structure, then it will be filled with the
compression properties that are supported for the surfaceFormat.
While the format of a presentable image refers to the encoding of each
pixel, the colorSpace determines how the presentation engine
interprets the pixel values.
A color space in this document refers to a specific color space (defined by
the chromaticities of its primaries and a white point in CIE Lab), and a
transfer function that is applied before storing or transmitting color data
in the given color space.
Possible values of VkSurfaceFormatKHR::colorSpace, specifying
supported color spaces of a presentation engine, are:
// Provided by VK_KHR_surface
typedef enum VkColorSpaceKHR {
VK_COLOR_SPACE_SRGB_NONLINEAR_KHR = 0,
// Provided by VK_EXT_swapchain_colorspace
VK_COLOR_SPACE_DISPLAY_P3_NONLINEAR_EXT = 1000104001,
// Provided by VK_EXT_swapchain_colorspace
VK_COLOR_SPACE_EXTENDED_SRGB_LINEAR_EXT = 1000104002,
// Provided by VK_EXT_swapchain_colorspace
VK_COLOR_SPACE_DISPLAY_P3_LINEAR_EXT = 1000104003,
// Provided by VK_EXT_swapchain_colorspace
VK_COLOR_SPACE_DCI_P3_NONLINEAR_EXT = 1000104004,
// Provided by VK_EXT_swapchain_colorspace
VK_COLOR_SPACE_BT709_LINEAR_EXT = 1000104005,
// Provided by VK_EXT_swapchain_colorspace
VK_COLOR_SPACE_BT709_NONLINEAR_EXT = 1000104006,
// Provided by VK_EXT_swapchain_colorspace
VK_COLOR_SPACE_BT2020_LINEAR_EXT = 1000104007,
// Provided by VK_EXT_swapchain_colorspace
VK_COLOR_SPACE_HDR10_ST2084_EXT = 1000104008,
// Provided by VK_EXT_swapchain_colorspace
VK_COLOR_SPACE_DOLBYVISION_EXT = 1000104009,
// Provided by VK_EXT_swapchain_colorspace
VK_COLOR_SPACE_HDR10_HLG_EXT = 1000104010,
// Provided by VK_EXT_swapchain_colorspace
VK_COLOR_SPACE_ADOBERGB_LINEAR_EXT = 1000104011,
// Provided by VK_EXT_swapchain_colorspace
VK_COLOR_SPACE_ADOBERGB_NONLINEAR_EXT = 1000104012,
// Provided by VK_EXT_swapchain_colorspace
VK_COLOR_SPACE_PASS_THROUGH_EXT = 1000104013,
// Provided by VK_EXT_swapchain_colorspace
VK_COLOR_SPACE_EXTENDED_SRGB_NONLINEAR_EXT = 1000104014,
// Provided by VK_AMD_display_native_hdr
VK_COLOR_SPACE_DISPLAY_NATIVE_AMD = 1000213000,
VK_COLORSPACE_SRGB_NONLINEAR_KHR = VK_COLOR_SPACE_SRGB_NONLINEAR_KHR,
// Provided by VK_EXT_swapchain_colorspace
VK_COLOR_SPACE_DCI_P3_LINEAR_EXT = VK_COLOR_SPACE_DISPLAY_P3_LINEAR_EXT,
} VkColorSpaceKHR;-
VK_COLOR_SPACE_SRGB_NONLINEAR_KHRspecifies support for the sRGB color space. -
VK_COLOR_SPACE_DISPLAY_P3_NONLINEAR_EXTspecifies support for the Display-P3 color space to be displayed using an sRGB-like EOTF (defined below). -
VK_COLOR_SPACE_EXTENDED_SRGB_LINEAR_EXTspecifies support for the extended sRGB color space to be displayed using a linear EOTF. -
VK_COLOR_SPACE_EXTENDED_SRGB_NONLINEAR_EXTspecifies support for the extended sRGB color space to be displayed using an sRGB EOTF. -
VK_COLOR_SPACE_DISPLAY_P3_LINEAR_EXTspecifies support for the Display-P3 color space to be displayed using a linear EOTF. -
VK_COLOR_SPACE_DCI_P3_NONLINEAR_EXTspecifies support for the DCI-P3 color space to be displayed using the DCI-P3 EOTF. Note that values in such an image are interpreted as XYZ encoded color data by the presentation engine. -
VK_COLOR_SPACE_BT709_LINEAR_EXTspecifies support for the BT709 color space to be displayed using a linear EOTF. -
VK_COLOR_SPACE_BT709_NONLINEAR_EXTspecifies support for the BT709 color space to be displayed using the SMPTE 170M EOTF. -
VK_COLOR_SPACE_BT2020_LINEAR_EXTspecifies support for the BT2020 color space to be displayed using a linear EOTF. -
VK_COLOR_SPACE_HDR10_ST2084_EXTspecifies support for the HDR10 (BT2020 color) space to be displayed using the SMPTE ST2084 Perceptual Quantizer (PQ) EOTF. -
VK_COLOR_SPACE_DOLBYVISION_EXTspecifies support for the Dolby Vision (BT2020 color space), proprietary encoding, to be displayed using the SMPTE ST2084 EOTF. -
VK_COLOR_SPACE_HDR10_HLG_EXTspecifies support for the HDR10 (BT2020 color space) to be displayed using the Hybrid Log Gamma (HLG) EOTF. -
VK_COLOR_SPACE_ADOBERGB_LINEAR_EXTspecifies support for the AdobeRGB color space to be displayed using a linear EOTF. -
VK_COLOR_SPACE_ADOBERGB_NONLINEAR_EXTspecifies support for the AdobeRGB color space to be displayed using the Gamma 2.2 EOTF. -
VK_COLOR_SPACE_PASS_THROUGH_EXTspecifies that color components are used “as is”. This is intended to allow applications to supply data for color spaces not described here. -
VK_COLOR_SPACE_DISPLAY_NATIVE_AMDspecifies support for the display’s native color space. This matches the color space expectations of AMD’s FreeSync2 standard, for displays supporting it.
|
Note
In the initial release of the |
|
Note
In older versions of this extension
|
|
Note
For a traditional “Linear” or non-gamma transfer function color space use
|
The color components of non-linear color space swapchain images must have had the appropriate transfer function applied. The color space selected for the swapchain image will not affect the processing of data written into the image by the implementation. Vulkan requires that all implementations support the sRGB transfer function by use of an SRGB pixel format. Other transfer functions, such as SMPTE 170M or SMPTE2084, can be performed by the application shader. This extension defines enums for VkColorSpaceKHR that correspond to the following color spaces:
| Name | Red Primary | Green Primary | Blue Primary | White-point | Transfer function |
|---|---|---|---|---|---|
DCI-P3 |
1.000, 0.000 |
0.000, 1.000 |
0.000, 0.000 |
0.3333, 0.3333 |
DCI P3 |
Display-P3 |
0.680, 0.320 |
0.265, 0.690 |
0.150, 0.060 |
0.3127, 0.3290 (D65) |
Display-P3 |
BT709 |
0.640, 0.330 |
0.300, 0.600 |
0.150, 0.060 |
0.3127, 0.3290 (D65) |
ITU (SMPTE 170M) |
sRGB |
0.640, 0.330 |
0.300, 0.600 |
0.150, 0.060 |
0.3127, 0.3290 (D65) |
sRGB |
extended sRGB |
0.640, 0.330 |
0.300, 0.600 |
0.150, 0.060 |
0.3127, 0.3290 (D65) |
extended sRGB |
HDR10_ST2084 |
0.708, 0.292 |
0.170, 0.797 |
0.131, 0.046 |
0.3127, 0.3290 (D65) |
ST2084 PQ |
DOLBYVISION |
0.708, 0.292 |
0.170, 0.797 |
0.131, 0.046 |
0.3127, 0.3290 (D65) |
ST2084 PQ |
HDR10_HLG |
0.708, 0.292 |
0.170, 0.797 |
0.131, 0.046 |
0.3127, 0.3290 (D65) |
HLG |
AdobeRGB |
0.640, 0.330 |
0.210, 0.710 |
0.150, 0.060 |
0.3127, 0.3290 (D65) |
AdobeRGB |
The transfer functions are described in the “Transfer Functions” chapter of the Khronos Data Format Specification.
Except Display-P3 OETF, which is:
where L is the linear value of a color component and E is the encoded value (as stored in the image in memory).
|
Note
For most uses, the sRGB OETF is equivalent. |
34.5.3. Surface Presentation Mode Support
To query the supported presentation modes for a surface, call:
// Provided by VK_KHR_surface
VkResult vkGetPhysicalDeviceSurfacePresentModesKHR(
VkPhysicalDevice physicalDevice,
VkSurfaceKHR surface,
uint32_t* pPresentModeCount,
VkPresentModeKHR* pPresentModes);-
physicalDeviceis the physical device that will be associated with the swapchain to be created, as described for vkCreateSwapchainKHR. -
surfaceis the surface that will be associated with the swapchain. -
pPresentModeCountis a pointer to an integer related to the number of presentation modes available or queried, as described below. -
pPresentModesis eitherNULLor a pointer to an array of VkPresentModeKHR values, indicating the supported presentation modes.
If pPresentModes is NULL, then the number of presentation modes
supported for the given surface is returned in
pPresentModeCount.
Otherwise, pPresentModeCount must point to a variable set by the user
to the number of elements in the pPresentModes array, and on return
the variable is overwritten with the number of values actually written to
pPresentModes.
If the value of pPresentModeCount is less than the number of
presentation modes supported, at most pPresentModeCount values will be
written, and VK_INCOMPLETE will be returned instead of
VK_SUCCESS, to indicate that not all the available modes were
returned.
If the VK_GOOGLE_surfaceless_query extension is enabled and
surface is VK_NULL_HANDLE, the values returned in
pPresentModes will only indicate support for
VK_PRESENT_MODE_FIFO_KHR,
VK_PRESENT_MODE_SHARED_DEMAND_REFRESH_KHR, and
VK_PRESENT_MODE_SHARED_CONTINUOUS_REFRESH_KHR.
To query support for any other present mode, a valid handle must be
provided in surface.
Alternatively, to query the supported presentation modes for a surface combined with select other fixed swapchain creation parameters, call:
// Provided by VK_EXT_full_screen_exclusive
VkResult vkGetPhysicalDeviceSurfacePresentModes2EXT(
VkPhysicalDevice physicalDevice,
const VkPhysicalDeviceSurfaceInfo2KHR* pSurfaceInfo,
uint32_t* pPresentModeCount,
VkPresentModeKHR* pPresentModes);-
physicalDeviceis the physical device that will be associated with the swapchain to be created, as described for vkCreateSwapchainKHR. -
pSurfaceInfois a pointer to a VkPhysicalDeviceSurfaceInfo2KHR structure describing the surface and other fixed parameters that would be consumed by vkCreateSwapchainKHR. -
pPresentModeCountis a pointer to an integer related to the number of presentation modes available or queried, as described below. -
pPresentModesis eitherNULLor a pointer to an array of VkPresentModeKHR values, indicating the supported presentation modes.
vkGetPhysicalDeviceSurfacePresentModes2EXT behaves similarly to
vkGetPhysicalDeviceSurfacePresentModesKHR, with the ability to specify
extended inputs via chained input structures.
Possible values of elements of the
vkGetPhysicalDeviceSurfacePresentModesKHR::pPresentModes array,
indicating the supported presentation modes for a surface, are:
// Provided by VK_KHR_surface
typedef enum VkPresentModeKHR {
VK_PRESENT_MODE_IMMEDIATE_KHR = 0,
VK_PRESENT_MODE_MAILBOX_KHR = 1,
VK_PRESENT_MODE_FIFO_KHR = 2,
VK_PRESENT_MODE_FIFO_RELAXED_KHR = 3,
// Provided by VK_KHR_shared_presentable_image
VK_PRESENT_MODE_SHARED_DEMAND_REFRESH_KHR = 1000111000,
// Provided by VK_KHR_shared_presentable_image
VK_PRESENT_MODE_SHARED_CONTINUOUS_REFRESH_KHR = 1000111001,
} VkPresentModeKHR;-
VK_PRESENT_MODE_IMMEDIATE_KHRspecifies that the presentation engine does not wait for a vertical blanking period to update the current image, meaning this mode may result in visible tearing. No internal queuing of presentation requests is needed, as the requests are applied immediately. -
VK_PRESENT_MODE_MAILBOX_KHRspecifies that the presentation engine waits for the next vertical blanking period to update the current image. Tearing cannot be observed. An internal single-entry queue is used to hold pending presentation requests. If the queue is full when a new presentation request is received, the new request replaces the existing entry, and any images associated with the prior entry become available for reuse by the application. One request is removed from the queue and processed during each vertical blanking period in which the queue is non-empty. -
VK_PRESENT_MODE_FIFO_KHRspecifies that the presentation engine waits for the next vertical blanking period to update the current image. Tearing cannot be observed. An internal queue is used to hold pending presentation requests. New requests are appended to the end of the queue, and one request is removed from the beginning of the queue and processed during each vertical blanking period in which the queue is non-empty. This is the only value ofpresentModethat is required to be supported. -
VK_PRESENT_MODE_FIFO_RELAXED_KHRspecifies that the presentation engine generally waits for the next vertical blanking period to update the current image. If a vertical blanking period has already passed since the last update of the current image then the presentation engine does not wait for another vertical blanking period for the update, meaning this mode may result in visible tearing in this case. This mode is useful for reducing visual stutter with an application that will mostly present a new image before the next vertical blanking period, but may occasionally be late, and present a new image just after the next vertical blanking period. An internal queue is used to hold pending presentation requests. New requests are appended to the end of the queue, and one request is removed from the beginning of the queue and processed during or after each vertical blanking period in which the queue is non-empty. -
VK_PRESENT_MODE_SHARED_DEMAND_REFRESH_KHRspecifies that the presentation engine and application have concurrent access to a single image, which is referred to as a shared presentable image. The presentation engine is only required to update the current image after a new presentation request is received. Therefore the application must make a presentation request whenever an update is required. However, the presentation engine may update the current image at any point, meaning this mode may result in visible tearing. -
VK_PRESENT_MODE_SHARED_CONTINUOUS_REFRESH_KHRspecifies that the presentation engine and application have concurrent access to a single image, which is referred to as a shared presentable image. The presentation engine periodically updates the current image on its regular refresh cycle. The application is only required to make one initial presentation request, after which the presentation engine must update the current image without any need for further presentation requests. The application can indicate the image contents have been updated by making a presentation request, but this does not guarantee the timing of when it will be updated. This mode may result in visible tearing if rendering to the image is not timed correctly.
The supported VkImageUsageFlagBits of the presentable images of a swapchain created for a surface may differ depending on the presentation mode, and can be determined as per the table below:
| Presentation mode | Image usage flags |
|---|---|
|
VkSurfaceCapabilitiesKHR:: |
|
VkSurfaceCapabilitiesKHR:: |
|
VkSurfaceCapabilitiesKHR:: |
|
VkSurfaceCapabilitiesKHR:: |
|
VkSharedPresentSurfaceCapabilitiesKHR:: |
|
VkSharedPresentSurfaceCapabilitiesKHR:: |
|
Note
For reference, the mode indicated by |
34.6. Full Screen Exclusive Control
Swapchains created with fullScreenExclusive set to
VK_FULL_SCREEN_EXCLUSIVE_APPLICATION_CONTROLLED_EXT must acquire and
release exclusive full-screen access explicitly, using the following
commands.
To acquire exclusive full-screen access for a swapchain, call:
// Provided by VK_EXT_full_screen_exclusive
VkResult vkAcquireFullScreenExclusiveModeEXT(
VkDevice device,
VkSwapchainKHR swapchain);-
deviceis the device associated withswapchain. -
swapchainis the swapchain to acquire exclusive full-screen access for.
A return value of VK_SUCCESS indicates that the swapchain
successfully acquired exclusive full-screen access.
The swapchain will retain this exclusivity until either the application
releases exclusive full-screen access with
vkReleaseFullScreenExclusiveModeEXT, destroys the swapchain, or if any
of the swapchain commands return
VK_ERROR_FULL_SCREEN_EXCLUSIVE_MODE_LOST_EXT indicating that the mode
was lost because of platform-specific changes.
If the swapchain was unable to acquire exclusive full-screen access to the
display then VK_ERROR_INITIALIZATION_FAILED is returned.
An application can attempt to acquire exclusive full-screen access again
for the same swapchain even if this command fails, or if
VK_ERROR_FULL_SCREEN_EXCLUSIVE_MODE_LOST_EXT has been returned by a
swapchain command.
To release exclusive full-screen access from a swapchain, call:
// Provided by VK_EXT_full_screen_exclusive
VkResult vkReleaseFullScreenExclusiveModeEXT(
VkDevice device,
VkSwapchainKHR swapchain);-
deviceis the device associated withswapchain. -
swapchainis the swapchain to release exclusive full-screen access from.
|
Note
Applications will not be able to present to |
34.7. Device Group Queries
A logical device that represents multiple physical devices may support presenting from images on more than one physical device, or combining images from multiple physical devices.
To query these capabilities, call:
// Provided by VK_VERSION_1_1 with VK_KHR_swapchain, VK_KHR_device_group with VK_KHR_surface
VkResult vkGetDeviceGroupPresentCapabilitiesKHR(
VkDevice device,
VkDeviceGroupPresentCapabilitiesKHR* pDeviceGroupPresentCapabilities);-
deviceis the logical device. -
pDeviceGroupPresentCapabilitiesis a pointer to a VkDeviceGroupPresentCapabilitiesKHR structure in which the device’s capabilities are returned.
The VkDeviceGroupPresentCapabilitiesKHR structure is defined as:
// Provided by VK_VERSION_1_1 with VK_KHR_swapchain, VK_KHR_device_group with VK_KHR_surface
typedef struct VkDeviceGroupPresentCapabilitiesKHR {
VkStructureType sType;
void* pNext;
uint32_t presentMask[VK_MAX_DEVICE_GROUP_SIZE];
VkDeviceGroupPresentModeFlagsKHR modes;
} VkDeviceGroupPresentCapabilitiesKHR;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
presentMaskis an array ofVK_MAX_DEVICE_GROUP_SIZEuint32_tmasks, where the mask at element i is non-zero if physical device i has a presentation engine, and where bit j is set in element i if physical device i can present swapchain images from physical device j. If element i is non-zero, then bit i must be set. -
modesis a bitmask of VkDeviceGroupPresentModeFlagBitsKHR indicating which device group presentation modes are supported.
modes always has VK_DEVICE_GROUP_PRESENT_MODE_LOCAL_BIT_KHR set.
The present mode flags are also used when presenting an image, in
VkDeviceGroupPresentInfoKHR::mode.
If a device group only includes a single physical device, then modes
must equal VK_DEVICE_GROUP_PRESENT_MODE_LOCAL_BIT_KHR.
Bits which may be set in
VkDeviceGroupPresentCapabilitiesKHR::modes, indicating which
device group presentation modes are supported, are:
// Provided by VK_VERSION_1_1 with VK_KHR_swapchain, VK_KHR_device_group with VK_KHR_surface
typedef enum VkDeviceGroupPresentModeFlagBitsKHR {
VK_DEVICE_GROUP_PRESENT_MODE_LOCAL_BIT_KHR = 0x00000001,
VK_DEVICE_GROUP_PRESENT_MODE_REMOTE_BIT_KHR = 0x00000002,
VK_DEVICE_GROUP_PRESENT_MODE_SUM_BIT_KHR = 0x00000004,
VK_DEVICE_GROUP_PRESENT_MODE_LOCAL_MULTI_DEVICE_BIT_KHR = 0x00000008,
} VkDeviceGroupPresentModeFlagBitsKHR;-
VK_DEVICE_GROUP_PRESENT_MODE_LOCAL_BIT_KHRspecifies that any physical device with a presentation engine can present its own swapchain images. -
VK_DEVICE_GROUP_PRESENT_MODE_REMOTE_BIT_KHRspecifies that any physical device with a presentation engine can present swapchain images from any physical device in itspresentMask. -
VK_DEVICE_GROUP_PRESENT_MODE_SUM_BIT_KHRspecifies that any physical device with a presentation engine can present the sum of swapchain images from any physical devices in itspresentMask. -
VK_DEVICE_GROUP_PRESENT_MODE_LOCAL_MULTI_DEVICE_BIT_KHRspecifies that multiple physical devices with a presentation engine can each present their own swapchain images.
// Provided by VK_VERSION_1_1 with VK_KHR_swapchain, VK_KHR_device_group with VK_KHR_surface
typedef VkFlags VkDeviceGroupPresentModeFlagsKHR;VkDeviceGroupPresentModeFlagsKHR is a bitmask type for setting a mask
of zero or more VkDeviceGroupPresentModeFlagBitsKHR.
Some surfaces may not be capable of using all the device group present modes.
To query the supported device group present modes for a particular surface, call:
// Provided by VK_VERSION_1_1 with VK_KHR_swapchain, VK_KHR_device_group with VK_KHR_surface
VkResult vkGetDeviceGroupSurfacePresentModesKHR(
VkDevice device,
VkSurfaceKHR surface,
VkDeviceGroupPresentModeFlagsKHR* pModes);-
deviceis the logical device. -
surfaceis the surface. -
pModesis a pointer to a VkDeviceGroupPresentModeFlagsKHR in which the supported device group present modes for the surface are returned.
The modes returned by this command are not invariant, and may change in response to the surface being moved, resized, or occluded. These modes must be a subset of the modes returned by vkGetDeviceGroupPresentCapabilitiesKHR.
Alternatively, to query the supported device group presentation modes for a surface combined with select other fixed swapchain creation parameters, call:
// Provided by VK_VERSION_1_1 with VK_EXT_full_screen_exclusive, VK_KHR_device_group with VK_EXT_full_screen_exclusive
VkResult vkGetDeviceGroupSurfacePresentModes2EXT(
VkDevice device,
const VkPhysicalDeviceSurfaceInfo2KHR* pSurfaceInfo,
VkDeviceGroupPresentModeFlagsKHR* pModes);-
deviceis the logical device. -
pSurfaceInfois a pointer to a VkPhysicalDeviceSurfaceInfo2KHR structure describing the surface and other fixed parameters that would be consumed by vkCreateSwapchainKHR. -
pModesis a pointer to a VkDeviceGroupPresentModeFlagsKHR in which the supported device group present modes for the surface are returned.
vkGetDeviceGroupSurfacePresentModes2EXT behaves similarly to
vkGetDeviceGroupSurfacePresentModesKHR, with the ability to specify
extended inputs via chained input structures.
When using VK_DEVICE_GROUP_PRESENT_MODE_LOCAL_MULTI_DEVICE_BIT_KHR,
the application may need to know which regions of the surface are used when
presenting locally on each physical device.
Presentation of swapchain images to this surface need only have valid
contents in the regions returned by this command.
To query a set of rectangles used in presentation on the physical device, call:
// Provided by VK_VERSION_1_1 with VK_KHR_swapchain, VK_KHR_device_group with VK_KHR_surface
VkResult vkGetPhysicalDevicePresentRectanglesKHR(
VkPhysicalDevice physicalDevice,
VkSurfaceKHR surface,
uint32_t* pRectCount,
VkRect2D* pRects);-
physicalDeviceis the physical device. -
surfaceis the surface. -
pRectCountis a pointer to an integer related to the number of rectangles available or queried, as described below. -
pRectsis eitherNULLor a pointer to an array of VkRect2D structures.
If pRects is NULL, then the number of rectangles used when
presenting the given surface is returned in pRectCount.
Otherwise, pRectCount must point to a variable set by the user to the
number of elements in the pRects array, and on return the variable is
overwritten with the number of structures actually written to pRects.
If the value of pRectCount is less than the number of rectangles, at
most pRectCount structures will be written, and VK_INCOMPLETE
will be returned instead of VK_SUCCESS, to indicate that not all the
available rectangles were returned.
The values returned by this command are not invariant, and may change in response to the surface being moved, resized, or occluded.
The rectangles returned by this command must not overlap.
34.8. Present Timing Queries
Traditional game and real-time-animation applications frequently use
VK_PRESENT_MODE_FIFO_KHR so that presentable images are updated during
the vertical blanking period of a given refresh cycle (RC) of the
presentation engine’s display.
This avoids the visual anomaly known as tearing.
However, synchronizing the presentation of images with the RC does not prevent all forms of visual anomalies. Stuttering occurs when the geometry for each presentable image is not accurately positioned for when that image will be displayed. The geometry may appear to move too little some RCs, and too much for others. Sometimes the animation appears to freeze, when the same image is used for more RCs than other images.
In order to minimize stuttering, an application needs to: 1) render
and present images at a consistent rate that is a multiple of the
presentation engine’s refresh rate; 2) correctly position its geometry
for when the presentable image will be displayed to the user.
Applications can benefit from communication of timing information with the
presentation engine and its display.
For example, applications can determine information about the refresh
rate of the display/compositor, can specify when an image should be
presented, and can determine when an image was actually presented.
This allows the application’s animation to look smooth to the user, with
no stuttering.
The
VK_EXT_present_timing
or
VK_GOOGLE_display_timing
extension allows an application to satisfy these needs.
The presentation engine’s display typically refreshes the pixels that are displayed to the user on a periodic basis. This period may be fixed (Fixed Refresh Rate, FRR) or variable (Variable Refresh Rate, VRR).
To enable present timing for a swapchain, add a
VkSwapchainPresentTimingCreateInfoEXT structure to the pNext
chain of VkSwapchainCreateInfoKHR.
The VkSwapchainPresentTimingCreateInfoEXT structure is defined as:
// Provided by VK_EXT_present_timing
typedef struct VkSwapchainPresentTimingCreateInfoEXT {
VkStructureType sType;
const void* pNext;
uint32_t presentTimingQueueSize;
VkPresentStageFlagsEXT presentStageQueries;
VkPresentStageFlagsEXT presentStageTarget;
VkBool32 presentAtRelativeTime;
} VkSwapchainPresentTimingCreateInfoEXT;-
sTypeis the type of this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
presentTimingQueueSizeis the size of the swapchain’s internal storage holding presentation timing results. -
presentStageQueriesis a VkPresentStageFlagsEXT mask specifying the stages that will be measured and reported by vkGetPastPresentationTimingEXT. -
presentStageTargetis zero or a VkPresentStageFlagsEXT value specifying which present stage to target when providing target present times to present operations. -
presentAtRelativeTimespecifies whether target present times are to be interpreted as relative times.
If presentStageTarget is not zero, a non-zero VkPresentTimeEXT
can be provided when presenting an image of the swapchain.
To query the presentation engine’s timing properties for a given swapchain, call:
// Provided by VK_EXT_present_timing
VkResult vkGetSwapchainTimingPropertiesEXT(
VkDevice device,
VkSwapchainKHR swapchain,
VkSwapchainTimingPropertiesEXT* pSwapchainTimingProperties);-
deviceis the device associated withswapchain. -
swapchainis the swapchain to obtain timing properties for. -
pSwapchainTimingPropertiesis a pointer to an instance of theVkSwapchainTimingPropertiesEXTstructure.
The VkSwapchainTimingPropertiesEXT structure is defined as:
// Provided by VK_EXT_present_timing
typedef struct VkSwapchainTimingPropertiesEXT {
VkStructureType sType;
const void* pNext;
uint64_t refreshDuration;
VkBool32 variableRefresh;
} VkSwapchainTimingPropertiesEXT;-
sTypeis the type of this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
refreshDurationis zero; or is an indication of the duration of a refresh cycle. If the presentation engine is operating as an FRR display, this is the number of nanoseconds from the start of one refresh cycle to the start of the next refresh cycle. If the presentation engine is operating as an VRR display (i.e. refresh cycles may have variable length), this is the minimum number of nanoseconds from the start of one refresh cycle to the start of the next refresh cycle. -
variableRefreshis undefined ifrefreshDurationis zero; otherwise it isVK_FALSEif the presentation engine is operating as a FRR display, orVK_TRUEif the presentation engine is operating as a VRR display.
Some platforms may not provide timing properties until after at least one
image has been presented to the swapchain. If timing properties
change for the swapchain, these same platforms may not provide
updated results until after at least one additional image has been
presented to the swapchain.
|
Note
The rate at which an application renders and presents new images is known as
the image present rate (IPR, a.k.a. frame rate).
The inverse of IPR, or the duration between each image present, is the image
present duration (IPD).
In order to provide a smooth, stutter-free animation, an application needs
its IPD to be a multiple of In order to determine a target IPD for a display (i.e. a multiple of
Adjustments to an application’s IPD may be needed because different views of an application’s geometry can take different amounts of time to render. For example, looking at the sky may take less time to render than looking at multiple, complex items in a room. In general, it is good to not frequently change IPD, as that can cause visual anomalies. Adjustments to a larger IPD because of late images should happen quickly, but adjustments to a smaller IPD should only happen if the periodic feedback of VkPastPresentationTimingEXT values indicates that the target IPD can be durably achieved. |
To query the time domain used by the presentation engine for a given swapchain, call:
// Provided by VK_EXT_present_timing
VkResult vkGetSwapchainTimeDomainsEXT(
VkDevice device,
VkSwapchainKHR swapchain,
uint32_t* pSwapchainTimeDomainCount,
VkSwapchainTimeDomainPropertiesEXT* pSwapchainTimeDomains);-
deviceis the device associated withswapchain. -
swapchainis the swapchain to obtain timing properties for. -
pSwapchainTimeDomainCountis a pointer to an integer related to the number of time domains available or queried, as described below. -
pSwapchainTimeDomainsis eitherNULLor a pointer to an array of VkSwapchainTimeDomainPropertiesEXT structs, indicating the supported time domains of the presentation engine for the swapchain.
If pSwapchainTimeDomains is NULL, then the number of time domains
supported for the given swapchain is returned in
pSwapchainTimeDomainCount (if this value is zero, swapchain
does not currently support display timing).
Otherwise, pSwapchainTimeDomainCount must point to a variable set by the user
to the number of elements in the pSwapchainTimeDomains array, and on return
the variable is overwritten with the number of values actually written to
pSwapchainTimeDomains.
If the value of pSwapchainTimeDomainCount is less than the number of
time domains supported, at most pSwapchainTimeDomainCount values will be
written.
If pSwapchainTimeDomainCount is smaller than the number of time domains
supported for the given swapchain, VK_INCOMPLETE will be returned
instead of VK_SUCCESS to indicate that not all the available values
were returned.
The VkSwapchainTimeDomainPropertiesEXT structure is defined as:
// Provided by VK_EXT_present_timing
typedef struct VkSwapchainTimeDomainPropertiesEXT {
VkStructureType sType;
void* pNext;
VkTimeDomainEXT timeDomain;
} VkSwapchainTimeDomainPropertiesEXT;-
sTypeis the type of this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
timeDomainis a VkTimeDomainEXT value representing a time domain that is available for the swapchain.
To set timing information for a swapchain, call:
// Provided by VK_EXT_present_timing
VkResult vkSetSwapchainTimingEXT(
VkDevice device,
VkSwapchainKHR swapchain,
const VkSwapchainTimingInfoEXT* pSwapchainTimingInfo);-
deviceis the device associated withswapchain. -
swapchainis the swapchain to obtain timing properties for. -
pSwapchainTimingInfoisNULLor a pointer to an instance of theVkSwapchainTimingInfoEXTstructure. IfNULL, display timing is disabled for the swapchain, otherwise enables display timing and specifies which time domain to use.
The VkSwapchainTimingInfoEXT structure is defined as:
// Provided by VK_EXT_present_timing
typedef struct VkSwapchainTimingInfoEXT {
VkStructureType sType;
const void* pNext;
VkTimeDomainEXT timeDomain;
} VkSwapchainTimingInfoEXT;-
sTypeis the type of this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
timeDomainis a VkTimeDomainEXT value representing the time domain that should be used with the swapchain.
The implementation maintains a limited amount of history of timing
information about previous presents, specified by
VkSwapchainPresentTimingCreateInfoEXT::presentTimingQueueSize
when creating a swapchain.
Because of the asynchronous nature of the presentation engine, the timing
information for a given vkQueuePresentKHR command only becomes
available some time later.
These time values should be asynchronously queried, and are returned if
available.
All time values are in nanoseconds, according to the time-domain being used.
To asynchronously query the presentation engine for newly-available timing information about one or more previous presents to a given swapchain, call:
// Provided by VK_EXT_present_timing
VkResult vkGetPastPresentationTimingEXT(
VkDevice device,
VkSwapchainKHR swapchain,
uint32_t* pPresentationTimingCount,
VkPastPresentationTimingEXT* pPresentationTimings);-
deviceis the device associated withswapchain. -
swapchainis the swapchain to obtain presentation timing information duration for. -
pPresentationTimingCountis a pointer to an integer related to the number ofVkPastPresentationTimingEXTstructures to query, as described below. -
pPresentationTimingsis eitherNULLor a pointer to an an array ofVkPastPresentationTimingEXTstructures.
If pPresentationTimings is NULL, then the number of available
timing records for the given swapchain is returned in
pPresentationTimingCount.
Otherwise, pPresentationTimingCount must point to a variable set by
the user to the number of elements in the pPresentationTimings array,
and on return the variable is overwritten with the number of structures
actually written to pPresentationTimings.
If the value of pPresentationTimingCount is less than the number of
newly-available timing records, at most pPresentationTimingCount
structures are written.
If pPresentationTimingCount is smaller than the number of
newly-available timing records for the given swapchain,
VK_INCOMPLETE is returned instead of VK_SUCCESS to indicate
that not all the available values were returned.
Elements of pPresentationTimings are arranged in ascending order of
present ids.
Timing information may become available out of order with regards to their associated vkQueuePresentKHR commands.
Because timing information for some present stages may be available earlier
than for some others, vkGetPastPresentationTimingEXT may return
incomplete results, containing only information for a subset of the
requested present stages. Further calls to
vkGetPastPresentationTimingEXT will keep providing all available
results for a previously incomplete entry until it is complete.
Upon return, zero or more slots of the swapchain internal timing
collection queue, equal to the number of completed entries written to
pPresentationTimings for which all present stages have been returned,
are made available for future vkQueuePresentKHR calls.
The VkPastPresentationTimingEXT structure is defined as:
// Provided by VK_EXT_present_timing
typedef struct VkPastPresentationTimingEXT {
VkStructureType sType;
const void* pNext;
uint64_t presentId;
uint64_t targetPresentTime;
uint32_t presentStageCount;
VkPresentStageTimeEXT* pPresentStages;
VkBool32 timingPropertiesChanged;
VkBool32 timeDomainChanged;
VkBool32 reportComplete;
} VkPastPresentationTimingEXT;-
sTypeis the type of this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
presentIdis an application-provided value that was given to a previousvkQueuePresentKHRcommand via VkPresentIdKHR::pPresentIds. It can be used to uniquely identify a previous present with the vkQueuePresentKHR command. If no VkPresentIdKHR was provided or if the specified present id value was zero,presentIdis zero. -
targetPresentTimeis an application-provided value that was given to a previous vkQueuePresentKHR command via VkPresentTimeEXT::targetPresentTime. If non-zero, it was used by the application to indicate that an image not be presented any sooner thantargetPresentTime, relative to the stage specified in VkSwapchainPresentTimingCreateInfoEXT::presentStageTarget. If theswapchainis using relative present times, it is zero and the actual present duration can be obtained by comparing thepPresentStagesresults of consecutive presents. -
presentStageCountis a count of items contained inpPresentStages. -
pPresentStagesisNULLor a pointer to an array of VkPresentStageTimeEXT providing timing information for each of the present stages requested in VkSwapchainPresentTimingCreateInfoEXT::presentStageQueries. -
timingPropertiesChangedisVK_TRUEif the swapchain’s timing properties have changed since the last time those properties were queried with vkGetSwapchainTimingPropertiesEXT, otherwise the properties have not changed. -
timeDomainChangedisVK_TRUEif the time domain enabled for the swapchain is not currently available. -
reportCompleteisVK_TRUEif the presentation engine has reported all the requested results inpPresentStages.
Timing information for some present stages may have a time value of 0, indicating that results for that present stage are not available.
For systems with multiple entities operating downstream of the presentation
engine, such as multiple displays, pPresentStages will return timing
results for at least one entity which has been affected by the presentation.
If pPresentStages is NULL, then the number of available present
stages reports is returned in presentStageCount. Otherwise,
presentStageCount must be set by the application to the number of
elements in the pPresentStages array, and on return the variable is
overwritten with the number of entries actually written to
pPresentStages. If the value of presentStageCount is less than
the number of available present stages reports, at most
presentStageCount will be written to pPresentStages.
If timeDomainChanged is VK_TRUE, the application must query
what time domains are available and enable present timing with a
currently-available time domain. If the currently-enabled time domain is the
opaque domain of VK_TIME_DOMAIN_SWAPCHAIN_LOCAL_EXT, it is possible
that VK_TIME_DOMAIN_SWAPCHAIN_LOCAL_EXT will be returned by
vkGetSwapchainTimeDomainsEXT. In such a case, the presentation engine
may have multiple opaque time domains that it is switching between.
If any of timeDomainChanged or timingPropertiesChanged is
VK_TRUE, an application must not compare the values of
pPresentStages with any other values, as the presentation engine may
not be able to provide accurate values.
The results for a given swapchain and present id are returned from
vkGetPastPresentationTimingEXT until reportComplete is
VK_TRUE and all available results have been reported in
pPresentStages.
|
Note
An application can determine its optimal IPD by using the
For a given target present stage, if If Frequent changes to an application’s IPD can cause visual artifacts. Therefore, it is wise for an application to avoid frequent changes to its IPD. |
|
Note
The presentation engine may change the timing properties of the
The available time domains for a swapchain may change for similar or
identical reasons.
Therefore, it is possible that the same event will cause both
|
To query the duration of a refresh cycle (RC) for the presentation engine’s display, call:
// Provided by VK_GOOGLE_display_timing
VkResult vkGetRefreshCycleDurationGOOGLE(
VkDevice device,
VkSwapchainKHR swapchain,
VkRefreshCycleDurationGOOGLE* pDisplayTimingProperties);-
deviceis the device associated withswapchain. -
swapchainis the swapchain to obtain the refresh duration for. -
pDisplayTimingPropertiesis a pointer to aVkRefreshCycleDurationGOOGLEstructure.
The VkRefreshCycleDurationGOOGLE structure is defined as:
// Provided by VK_GOOGLE_display_timing
typedef struct VkRefreshCycleDurationGOOGLE {
uint64_t refreshDuration;
} VkRefreshCycleDurationGOOGLE;-
refreshDurationis the number of nanoseconds from the start of one refresh cycle to the next.
The implementation will maintain a limited amount of history of timing
information about previous presents.
Because of the asynchronous nature of the presentation engine, the timing
information for a given vkQueuePresentKHR command will become
available some time later.
These time values can be asynchronously queried, and will be returned if
available.
All time values are in nanoseconds, relative to a monotonically-increasing
clock (e.g. CLOCK_MONOTONIC (see clock_gettime(2)) on Android and Linux).
To asynchronously query the presentation engine, for newly-available timing information about one or more previous presents to a given swapchain, call:
// Provided by VK_GOOGLE_display_timing
VkResult vkGetPastPresentationTimingGOOGLE(
VkDevice device,
VkSwapchainKHR swapchain,
uint32_t* pPresentationTimingCount,
VkPastPresentationTimingGOOGLE* pPresentationTimings);-
deviceis the device associated withswapchain. -
swapchainis the swapchain to obtain presentation timing information duration for. -
pPresentationTimingCountis a pointer to an integer related to the number ofVkPastPresentationTimingGOOGLEstructures to query, as described below. -
pPresentationTimingsis eitherNULLor a pointer to an array ofVkPastPresentationTimingGOOGLEstructures.
If pPresentationTimings is NULL, then the number of newly-available
timing records for the given swapchain is returned in
pPresentationTimingCount.
Otherwise, pPresentationTimingCount must point to a variable set by
the user to the number of elements in the pPresentationTimings array,
and on return the variable is overwritten with the number of structures
actually written to pPresentationTimings.
If the value of pPresentationTimingCount is less than the number of
newly-available timing records, at most pPresentationTimingCount
structures will be written, and VK_INCOMPLETE will be returned instead
of VK_SUCCESS, to indicate that not all the available timing records
were returned.
The VkPastPresentationTimingGOOGLE structure is defined as:
// Provided by VK_GOOGLE_display_timing
typedef struct VkPastPresentationTimingGOOGLE {
uint32_t presentID;
uint64_t desiredPresentTime;
uint64_t actualPresentTime;
uint64_t earliestPresentTime;
uint64_t presentMargin;
} VkPastPresentationTimingGOOGLE;-
presentIDis an application-provided value that was given to a previousvkQueuePresentKHRcommand via VkPresentTimeGOOGLE::presentID(see below). It can be used to uniquely identify a previous present with the vkQueuePresentKHR command. -
desiredPresentTimeis an application-provided value that was given to a previous vkQueuePresentKHR command via VkPresentTimeGOOGLE::desiredPresentTime. If non-zero, it was used by the application to indicate that an image not be presented any sooner thandesiredPresentTime. -
actualPresentTimeis the time when the image of theswapchainwas actually displayed. -
earliestPresentTimeis the time when the image of theswapchaincould have been displayed. This may differ fromactualPresentTimeif the application requested that the image be presented no sooner than VkPresentTimeGOOGLE::desiredPresentTime. -
presentMarginis an indication of how early thevkQueuePresentKHRcommand was processed compared to how soon it needed to be processed, and still be presented atearliestPresentTime.
The results for a given swapchain and presentID are only
returned once from vkGetPastPresentationTimingGOOGLE.
The application can use the VkPastPresentationTimingGOOGLE values to
occasionally adjust its timing.
For example, if actualPresentTime is later than expected (e.g. one
refreshDuration late), the application may increase its target IPD to
a higher multiple of refreshDuration (e.g. decrease its frame rate
from 60Hz to 30Hz).
If actualPresentTime and earliestPresentTime are consistently
different, and if presentMargin is consistently large enough, the
application may decrease its target IPD to a smaller multiple of
refreshDuration (e.g. increase its frame rate from 30Hz to 60Hz).
If actualPresentTime and earliestPresentTime are same, and if
presentMargin is consistently high, the application may delay the
start of its input-render-present loop in order to decrease the latency
between user input and the corresponding present (always leaving some margin
in case a new image takes longer to render than the previous image).
An application that desires its target IPD to always be the same as
refreshDuration, can also adjust features until
actualPresentTime is never late and presentMargin is
satisfactory.
The full VK_GOOGLE_display_timing extension semantics are described
for swapchains created with VK_PRESENT_MODE_FIFO_KHR.
For example, non-zero values of
VkPresentTimeGOOGLE::desiredPresentTime must be honored, and
vkGetPastPresentationTimingGOOGLE should return a
VkPastPresentationTimingGOOGLE structure with valid values for all
images presented with vkQueuePresentKHR.
The semantics for other present modes are as follows:
-
VK_PRESENT_MODE_IMMEDIATE_KHR. The presentation engine may ignore non-zero values ofVkPresentTimeGOOGLE::desiredPresentTimein favor of presenting immediately. The value ofVkPastPresentationTimingGOOGLE::earliestPresentTimemust be the same asVkPastPresentationTimingGOOGLE::actualPresentTime, which should be when the presentation engine displayed the image. -
VK_PRESENT_MODE_MAILBOX_KHR. The intention of using this present mode with this extension is to handle cases where an image is presented late, and the next image is presented soon enough to replace it at the next vertical blanking period. For images that are displayed to the user, the value ofVkPastPresentationTimingGOOGLE::actualPresentTimemust be when the image was displayed. For images that are not displayed to the user,vkGetPastPresentationTimingGOOGLEmay not return aVkPastPresentationTimingGOOGLEstructure, or it may return aVkPastPresentationTimingGOOGLEstructure with the value of zero for bothVkPastPresentationTimingGOOGLE::actualPresentTimeandVkPastPresentationTimingGOOGLE::earliestPresentTime. It is possible that an application can submit images withVkPresentTimeGOOGLE::desiredPresentTimevalues such that new images may not be displayed. For example, ifVkPresentTimeGOOGLE::desiredPresentTimeis far enough in the future that an image is not presented beforevkQueuePresentKHRis called to present another image, the first image will not be displayed to the user. If the application continues to do that, the presentation engine may not display new images. -
VK_PRESENT_MODE_FIFO_RELAXED_KHR. For images that are presented in time to be displayed at the next vertical blanking period, the semantics are identical as forVK_PRESENT_MODE_FIFO_RELAXED_KHR. For images that are presented late, and are displayed after the start of the vertical blanking period (i.e. with tearing), the values ofVkPastPresentationTimingGOOGLEmay be treated as if the image was displayed at the start of the vertical blanking period, or may be treated the same as forVK_PRESENT_MODE_IMMEDIATE_KHR.
34.9. Present Wait
Applications wanting to control the pacing of the application by monitoring when presentation processes have completed to limit the number of outstanding images queued for presentation, need to have a method of being signaled during the presentation process.
Using
the VK_GOOGLE_display_timing extension
applications can discover when images were presented, but only
asynchronously.
Providing a mechanism which allows applications to block, waiting for a specific step of the presentation process to complete allows them to control the amount of outstanding work (and hence the potential lag in responding to user input or changes in the rendering environment).
The VK_KHR_present_wait extension allows applications to tell the
presentation engine at the vkQueuePresentKHR call that it plans on
waiting for presentation by passing a VkPresentIdKHR structure.
The presentId passed in that structure may then be passed to a future
vkWaitForPresentKHR call to cause the application to block until that
presentation is finished.
34.10. WSI Swapchain
A swapchain object (a.k.a.
swapchain) provides the ability to present rendering results to a surface.
Swapchain objects are represented by VkSwapchainKHR handles:
// Provided by VK_KHR_swapchain
VK_DEFINE_NON_DISPATCHABLE_HANDLE(VkSwapchainKHR)A swapchain is an abstraction for an array of presentable images that are
associated with a surface.
The presentable images are represented by VkImage objects created by
the platform.
One image (which can be an array image for multiview/stereoscopic-3D
surfaces) is displayed at a time, but multiple images can be queued for
presentation.
An application renders to the image, and then queues the image for
presentation to the surface.
A native window cannot be associated with more than one non-retired swapchain at a time. Further, swapchains cannot be created for native windows that have a non-Vulkan graphics API surface associated with them.
|
Note
The presentation engine is an abstraction for the platform’s compositor or display engine. The presentation engine may be synchronous or asynchronous with respect to the application and/or logical device. Some implementations may use the device’s graphics queue or dedicated presentation hardware to perform presentation. |
The presentable images of a swapchain are owned by the presentation engine. An application can acquire use of a presentable image from the presentation engine. Use of a presentable image must occur only after the image is returned by vkAcquireNextImageKHR, and before it is released by vkQueuePresentKHR. This includes transitioning the image layout and rendering commands.
An application can acquire use of a presentable image with vkAcquireNextImageKHR. After acquiring a presentable image and before modifying it, the application must use a synchronization primitive to ensure that the presentation engine has finished reading from the image. The application can then transition the image’s layout, queue rendering commands to it, etc. Finally, the application presents the image with vkQueuePresentKHR, which releases the acquisition of the image. The application can also release the acquisition of the image through vkReleaseSwapchainImagesEXT, if the image is not in use by the device, and skip the present operation.
The presentation engine controls the order in which presentable images are acquired for use by the application.
|
Note
This allows the platform to handle situations which require out-of-order return of images after presentation. At the same time, it allows the application to generate command buffers referencing all of the images in the swapchain at initialization time, rather than in its main loop. |
How this all works is described below.
If a swapchain is created with presentMode set to either
VK_PRESENT_MODE_SHARED_DEMAND_REFRESH_KHR or
VK_PRESENT_MODE_SHARED_CONTINUOUS_REFRESH_KHR, a single presentable
image can be acquired, referred to as a shared presentable image.
A shared presentable image may be concurrently accessed by the application
and the presentation engine, without transitioning the image’s layout after
it is initially presented.
-
With
VK_PRESENT_MODE_SHARED_DEMAND_REFRESH_KHR, the presentation engine is only required to update to the latest contents of a shared presentable image after a present. The application must callvkQueuePresentKHRto guarantee an update. However, the presentation engine may update from it at any time. -
With
VK_PRESENT_MODE_SHARED_CONTINUOUS_REFRESH_KHR, the presentation engine will automatically present the latest contents of a shared presentable image during every refresh cycle. The application is only required to make one initial call tovkQueuePresentKHR, after which the presentation engine will update from it without any need for further present calls. The application can indicate the image contents have been updated by callingvkQueuePresentKHR, but this does not guarantee the timing of when updates will occur.
The presentation engine may access a shared presentable image at any time after it is first presented. To avoid tearing, an application should coordinate access with the presentation engine. This requires presentation engine timing information through platform-specific mechanisms and ensuring that color attachment writes are made available during the portion of the presentation engine’s refresh cycle they are intended for.
|
Note
The |
In order to query a swapchain’s status when rendering to a shared presentable image, call:
// Provided by VK_KHR_shared_presentable_image
VkResult vkGetSwapchainStatusKHR(
VkDevice device,
VkSwapchainKHR swapchain);-
deviceis the device associated withswapchain. -
swapchainis the swapchain to query.
The possible return values for vkGetSwapchainStatusKHR should be
interpreted as follows:
-
VK_SUCCESSspecifies the presentation engine is presenting the contents of the shared presentable image, as per the swapchain’s VkPresentModeKHR. -
VK_SUBOPTIMAL_KHRthe swapchain no longer matches the surface properties exactly, but the presentation engine is presenting the contents of the shared presentable image, as per the swapchain’s VkPresentModeKHR. -
VK_ERROR_OUT_OF_DATE_KHRthe surface has changed in such a way that it is no longer compatible with the swapchain. -
VK_ERROR_SURFACE_LOST_KHRthe surface is no longer available.
|
Note
The swapchain state may be cached by implementations, so applications
should regularly call |
To create a swapchain, call:
// Provided by VK_KHR_swapchain
VkResult vkCreateSwapchainKHR(
VkDevice device,
const VkSwapchainCreateInfoKHR* pCreateInfo,
const VkAllocationCallbacks* pAllocator,
VkSwapchainKHR* pSwapchain);-
deviceis the device to create the swapchain for. -
pCreateInfois a pointer to a VkSwapchainCreateInfoKHR structure specifying the parameters of the created swapchain. -
pAllocatoris the allocator used for host memory allocated for the swapchain object when there is no more specific allocator available (see Memory Allocation). -
pSwapchainis a pointer to a VkSwapchainKHR handle in which the created swapchain object will be returned.
As mentioned above, if vkCreateSwapchainKHR succeeds, it will return a
handle to a swapchain containing an array of at least
pCreateInfo->minImageCount presentable images.
While acquired by the application, presentable images can be used in any way that equivalent non-presentable images can be used. A presentable image is equivalent to a non-presentable image created with the following VkImageCreateInfo parameters:
VkImageCreateInfo Field |
Value |
|---|---|
|
all other bits are unset |
|
|
|
|
|
{ |
|
1 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
The pCreateInfo->surface must not be destroyed until after the
swapchain is destroyed.
If oldSwapchain is VK_NULL_HANDLE, and
the native window referred to by pCreateInfo->surface is already
associated with a Vulkan swapchain, VK_ERROR_NATIVE_WINDOW_IN_USE_KHR
must be returned.
If the native window referred to by pCreateInfo->surface is already
associated with a non-Vulkan graphics API surface,
VK_ERROR_NATIVE_WINDOW_IN_USE_KHR must be returned.
The native window referred to by pCreateInfo->surface must not become
associated with a non-Vulkan graphics API surface before all associated
Vulkan swapchains have been destroyed.
vkCreateSwapchainKHR will return VK_ERROR_DEVICE_LOST if the
logical device was lost.
The VkSwapchainKHR is a child of the device, and must be
destroyed before the device.
However, VkSurfaceKHR is not a child of any VkDevice and is not
affected by the lost device.
After successfully recreating a VkDevice, the same VkSurfaceKHR
can be used to create a new VkSwapchainKHR, provided the previous one
was destroyed.
If the oldSwapchain parameter of pCreateInfo is a valid
swapchain, which has exclusive full-screen access, that access is released
from pCreateInfo->oldSwapchain.
If the command succeeds in this case, the newly created swapchain will
automatically acquire exclusive full-screen access from
pCreateInfo->oldSwapchain.
|
Note
This implicit transfer is intended to avoid exiting and entering full-screen exclusive mode, which may otherwise cause unwanted visual updates to the display. |
In some cases, swapchain creation may fail if exclusive full-screen mode is
requested for application control, but for some implementation-specific
reason exclusive full-screen access is unavailable for the particular
combination of parameters provided.
If this occurs, VK_ERROR_INITIALIZATION_FAILED will be returned.
|
Note
In particular, it will fail if the |
If the pNext chain of VkSwapchainCreateInfoKHR includes a
VkSwapchainPresentBarrierCreateInfoNV structure, then that structure
includes additional swapchain creation parameters specific to the present
barrier.
Swapchain creation may fail if the state of the current system restricts
the usage of the present barrier feature
VkSurfaceCapabilitiesPresentBarrierNV, or a swapchain itself does not
satisfy all the required conditions.
In this scenario VK_ERROR_INITIALIZATION_FAILED is returned.
When the VkSurfaceKHR in VkSwapchainCreateInfoKHR is a display
surface, then the VkDisplayModeKHR in display surface’s
VkDisplaySurfaceCreateInfoKHR is associated with a particular
VkDisplayKHR.
Swapchain creation may fail if that VkDisplayKHR is not acquired by
the application.
In this scenario VK_ERROR_INITIALIZATION_FAILED is returned.
The VkSwapchainCreateInfoKHR structure is defined as:
// Provided by VK_KHR_swapchain
typedef struct VkSwapchainCreateInfoKHR {
VkStructureType sType;
const void* pNext;
VkSwapchainCreateFlagsKHR flags;
VkSurfaceKHR surface;
uint32_t minImageCount;
VkFormat imageFormat;
VkColorSpaceKHR imageColorSpace;
VkExtent2D imageExtent;
uint32_t imageArrayLayers;
VkImageUsageFlags imageUsage;
VkSharingMode imageSharingMode;
uint32_t queueFamilyIndexCount;
const uint32_t* pQueueFamilyIndices;
VkSurfaceTransformFlagBitsKHR preTransform;
VkCompositeAlphaFlagBitsKHR compositeAlpha;
VkPresentModeKHR presentMode;
VkBool32 clipped;
VkSwapchainKHR oldSwapchain;
} VkSwapchainCreateInfoKHR;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
flagsis a bitmask of VkSwapchainCreateFlagBitsKHR indicating parameters of the swapchain creation. -
surfaceis the surface onto which the swapchain will present images. If the creation succeeds, the swapchain becomes associated withsurface. -
minImageCountis the minimum number of presentable images that the application needs. The implementation will either create the swapchain with at least that many images, or it will fail to create the swapchain. -
imageFormatis a VkFormat value specifying the format the swapchain image(s) will be created with. -
imageColorSpaceis a VkColorSpaceKHR value specifying the way the swapchain interprets image data. -
imageExtentis the size (in pixels) of the swapchain image(s). The behavior is platform-dependent if the image extent does not match the surface’scurrentExtentas returned byvkGetPhysicalDeviceSurfaceCapabilitiesKHR.NoteOn some platforms, it is normal that
maxImageExtentmay become(0, 0), for example when the window is minimized. In such a case, it is not possible to create a swapchain due to the Valid Usage requirements , unless scaling is selected through VkSwapchainPresentScalingCreateInfoEXT, if supported . -
imageArrayLayersis the number of views in a multiview/stereo surface. For non-stereoscopic-3D applications, this value is 1. -
imageUsageis a bitmask of VkImageUsageFlagBits describing the intended usage of the (acquired) swapchain images. -
imageSharingModeis the sharing mode used for the image(s) of the swapchain. -
queueFamilyIndexCountis the number of queue families having access to the image(s) of the swapchain whenimageSharingModeisVK_SHARING_MODE_CONCURRENT. -
pQueueFamilyIndicesis a pointer to an array of queue family indices having access to the images(s) of the swapchain whenimageSharingModeisVK_SHARING_MODE_CONCURRENT. -
preTransformis a VkSurfaceTransformFlagBitsKHR value describing the transform, relative to the presentation engine’s natural orientation, applied to the image content prior to presentation. If it does not match thecurrentTransformvalue returned byvkGetPhysicalDeviceSurfaceCapabilitiesKHR, the presentation engine will transform the image content as part of the presentation operation. -
compositeAlphais a VkCompositeAlphaFlagBitsKHR value indicating the alpha compositing mode to use when this surface is composited together with other surfaces on certain window systems. -
presentModeis the presentation mode the swapchain will use. A swapchain’s present mode determines how incoming present requests will be processed and queued internally. -
clippedspecifies whether the Vulkan implementation is allowed to discard rendering operations that affect regions of the surface that are not visible.-
If set to
VK_TRUE, the presentable images associated with the swapchain may not own all of their pixels. Pixels in the presentable images that correspond to regions of the target surface obscured by another window on the desktop, or subject to some other clipping mechanism will have undefined content when read back. Fragment shaders may not execute for these pixels, and thus any side effects they would have had will not occur. SettingVK_TRUEdoes not guarantee any clipping will occur, but allows more efficient presentation methods to be used on some platforms. -
If set to
VK_FALSE, presentable images associated with the swapchain will own all of the pixels they contain.NoteApplications should set this value to
VK_TRUEif they do not expect to read back the content of presentable images before presenting them or after reacquiring them, and if their fragment shaders do not have any side effects that require them to run for all pixels in the presentable image.
-
-
oldSwapchainis VK_NULL_HANDLE, or the existing non-retired swapchain currently associated withsurface. Providing a validoldSwapchainmay aid in the resource reuse, and also allows the application to still present any images that are already acquired from it.
Upon calling vkCreateSwapchainKHR with an oldSwapchain that is
not VK_NULL_HANDLE, oldSwapchain is retired — even if creation
of the new swapchain fails.
The new swapchain is created in the non-retired state whether or not
oldSwapchain is VK_NULL_HANDLE.
Upon calling vkCreateSwapchainKHR with an oldSwapchain that is
not VK_NULL_HANDLE, any images from oldSwapchain that are not
acquired by the application may be freed by the implementation, which may
occur even if creation of the new swapchain fails.
The application can destroy oldSwapchain to free all memory
associated with oldSwapchain.
|
Note
Multiple retired swapchains can be associated with the same
After The application can continue to use a shared presentable image obtained
from |
Bits which can be set in VkSwapchainCreateInfoKHR::flags,
specifying parameters of swapchain creation, are:
// Provided by VK_KHR_swapchain
typedef enum VkSwapchainCreateFlagBitsKHR {
// Provided by VK_VERSION_1_1 with VK_KHR_swapchain, VK_KHR_device_group with VK_KHR_swapchain
VK_SWAPCHAIN_CREATE_SPLIT_INSTANCE_BIND_REGIONS_BIT_KHR = 0x00000001,
// Provided by VK_VERSION_1_1 with VK_KHR_swapchain
VK_SWAPCHAIN_CREATE_PROTECTED_BIT_KHR = 0x00000002,
// Provided by VK_KHR_swapchain_mutable_format
VK_SWAPCHAIN_CREATE_MUTABLE_FORMAT_BIT_KHR = 0x00000004,
// Provided by VK_EXT_swapchain_maintenance1
VK_SWAPCHAIN_CREATE_DEFERRED_MEMORY_ALLOCATION_BIT_EXT = 0x00000008,
} VkSwapchainCreateFlagBitsKHR;-
VK_SWAPCHAIN_CREATE_SPLIT_INSTANCE_BIND_REGIONS_BIT_KHRspecifies that images created from the swapchain (i.e. with theswapchainmember of VkImageSwapchainCreateInfoKHR set to this swapchain’s handle) must useVK_IMAGE_CREATE_SPLIT_INSTANCE_BIND_REGIONS_BIT. -
VK_SWAPCHAIN_CREATE_PROTECTED_BIT_KHRspecifies that images created from the swapchain are protected images. -
VK_SWAPCHAIN_CREATE_MUTABLE_FORMAT_BIT_KHRspecifies that the images of the swapchain can be used to create aVkImageViewwith a different format than what the swapchain was created with. The list of allowed image view formats is specified by adding a VkImageFormatListCreateInfo structure to thepNextchain of VkSwapchainCreateInfoKHR. In addition, this flag also specifies that the swapchain can be created with usage flags that are not supported for the format the swapchain is created with but are supported for at least one of the allowed image view formats. -
VK_SWAPCHAIN_CREATE_DEFERRED_MEMORY_ALLOCATION_BIT_EXTspecifies that the implementation may defer allocation of memory associated with each swapchain image until its index is to be returned from vkAcquireNextImageKHR or vkAcquireNextImage2KHR for the first time.
// Provided by VK_KHR_swapchain
typedef VkFlags VkSwapchainCreateFlagsKHR;VkSwapchainCreateFlagsKHR is a bitmask type for setting a mask of zero
or more VkSwapchainCreateFlagBitsKHR.
If the pNext chain of VkSwapchainCreateInfoKHR includes a
VkDeviceGroupSwapchainCreateInfoKHR structure, then that structure
includes a set of device group present modes that the swapchain can be used
with.
The VkDeviceGroupSwapchainCreateInfoKHR structure is defined as:
// Provided by VK_VERSION_1_1 with VK_KHR_swapchain, VK_KHR_device_group with VK_KHR_swapchain
typedef struct VkDeviceGroupSwapchainCreateInfoKHR {
VkStructureType sType;
const void* pNext;
VkDeviceGroupPresentModeFlagsKHR modes;
} VkDeviceGroupSwapchainCreateInfoKHR;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
modesis a bitfield of modes that the swapchain can be used with.
If this structure is not present, modes is considered to be
VK_DEVICE_GROUP_PRESENT_MODE_LOCAL_BIT_KHR.
If the pNext chain of VkSwapchainCreateInfoKHR includes a
VkSwapchainDisplayNativeHdrCreateInfoAMD structure, then that
structure includes additional swapchain creation parameters specific to
display native HDR support.
The VkSwapchainDisplayNativeHdrCreateInfoAMD structure is defined as:
// Provided by VK_AMD_display_native_hdr
typedef struct VkSwapchainDisplayNativeHdrCreateInfoAMD {
VkStructureType sType;
const void* pNext;
VkBool32 localDimmingEnable;
} VkSwapchainDisplayNativeHdrCreateInfoAMD;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
localDimmingEnablespecifies whether local dimming is enabled for the swapchain.
If the pNext chain of VkSwapchainCreateInfoKHR does not include
this structure, the default value for localDimmingEnable is
VK_TRUE, meaning local dimming is initially enabled for the swapchain.
The local dimming HDR setting may also be changed over the life of a swapchain by calling:
// Provided by VK_AMD_display_native_hdr
void vkSetLocalDimmingAMD(
VkDevice device,
VkSwapchainKHR swapChain,
VkBool32 localDimmingEnable);-
deviceis the device associated withswapChain. -
swapChainhandle to enable local dimming. -
localDimmingEnablespecifies whether local dimming is enabled for the swapchain.
If the pNext chain of VkSwapchainCreateInfoKHR includes a
VkSurfaceFullScreenExclusiveInfoEXT structure, then that structure
specifies the application’s preferred full-screen presentation behavior.
If this structure is not present, fullScreenExclusive is considered to
be VK_FULL_SCREEN_EXCLUSIVE_DEFAULT_EXT.
To enable surface counters when creating a swapchain, add a
VkSwapchainCounterCreateInfoEXT structure to the pNext chain of
VkSwapchainCreateInfoKHR.
VkSwapchainCounterCreateInfoEXT is defined as:
// Provided by VK_EXT_display_control
typedef struct VkSwapchainCounterCreateInfoEXT {
VkStructureType sType;
const void* pNext;
VkSurfaceCounterFlagsEXT surfaceCounters;
} VkSwapchainCounterCreateInfoEXT;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
surfaceCountersis a bitmask of VkSurfaceCounterFlagBitsEXT specifying surface counters to enable for the swapchain.
The requested counters become active when the first presentation command for the associated swapchain is processed by the presentation engine. To query the value of an active counter, use:
// Provided by VK_EXT_display_control
VkResult vkGetSwapchainCounterEXT(
VkDevice device,
VkSwapchainKHR swapchain,
VkSurfaceCounterFlagBitsEXT counter,
uint64_t* pCounterValue);-
deviceis the VkDevice associated withswapchain. -
swapchainis the swapchain from which to query the counter value. -
counteris a VkSurfaceCounterFlagBitsEXT value specifying the counter to query. -
pCounterValuewill return the current value of the counter.
If a counter is not available because the swapchain is out of date, the
implementation may return VK_ERROR_OUT_OF_DATE_KHR.
To specify compression properties for the swapchain images in this
swapchain, add a VkImageCompressionControlEXT structure to the
pNext chain of the VkSwapchainCreateInfoKHR structure.
Applications can modify the presentation mode used by the swapchain on a
per-presentation basis.
However, all presentation modes the application intends to use with the
swapchain must be specified at swapchain creation time.
To specify more than one presentation mode when creating a swapchain,
include the VkSwapchainPresentModesCreateInfoEXT structure in the
pNext chain of the VkSwapchainCreateInfoKHR structure.
The VkSwapchainPresentModesCreateInfoEXT structure is defined as:
// Provided by VK_EXT_swapchain_maintenance1
typedef struct VkSwapchainPresentModesCreateInfoEXT {
VkStructureType sType;
const void* pNext;
uint32_t presentModeCount;
const VkPresentModeKHR* pPresentModes;
} VkSwapchainPresentModesCreateInfoEXT;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
presentModeCountis the number of presentation modes provided. -
pPresentModesis a list of presentation modes withpresentModeCountentries
When an application presents a swapchain image with dimensions different than those of the target surface, different behavior is possible on different platforms per their respective specifications:
-
Presentation fails and
VK_ERROR_OUT_OF_DATE_KHRis returned -
Scaling is done and
VK_SUCCESSorVK_SUBOPTIMAL_KHRis returned -
Unspecified scaling using an arbitrary combination of stretching, centering and/or clipping.
Applications can define specific behavior when creating a swapchain by
including the VkSwapchainPresentScalingCreateInfoEXT structure in the
pNext chain of the VkSwapchainCreateInfoKHR structure.
The VkSwapchainPresentScalingCreateInfoEXT structure is defined as:
// Provided by VK_EXT_swapchain_maintenance1
typedef struct VkSwapchainPresentScalingCreateInfoEXT {
VkStructureType sType;
const void* pNext;
VkPresentScalingFlagsEXT scalingBehavior;
VkPresentGravityFlagsEXT presentGravityX;
VkPresentGravityFlagsEXT presentGravityY;
} VkSwapchainPresentScalingCreateInfoEXT;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
scalingBehavioris0or the scaling method to use when the dimensions of the surface and swapchain images differ. -
presentGravityXis0or the x-axis direction in which swapchain image pixels gravitate relative to the surface whenscalingBehaviordoes not result in a one-to-one pixel mapping between the scaled swapchain image and the surface. -
presentGravityYis0or the y-axis direction in which swapchain image pixels gravitate relative to the surface whenscalingBehaviordoes not result in a one-to-one pixel mapping between the scaled swapchain image and the surface.
If scalingBehavior is 0, the result of presenting a swapchain image
with dimensions that do not match the surface dimensions is implementation
and platform-dependent.
If presentGravityX or presentGravityY are 0, the presentation
gravity must match that defined by the native platform surface on platforms
which define surface gravity.
To destroy a swapchain object call:
// Provided by VK_KHR_swapchain
void vkDestroySwapchainKHR(
VkDevice device,
VkSwapchainKHR swapchain,
const VkAllocationCallbacks* pAllocator);-
deviceis the VkDevice associated withswapchain. -
swapchainis the swapchain to destroy. -
pAllocatoris the allocator used for host memory allocated for the swapchain object when there is no more specific allocator available (see Memory Allocation).
The application must not destroy a swapchain until after completion of all
outstanding operations on images that were acquired from the swapchain.
swapchain and all associated VkImage handles are destroyed, and
must not be acquired or used any more by the application.
The memory of each VkImage will only be freed after that image is no
longer used by the presentation engine.
For example, if one image of the swapchain is being displayed in a window,
the memory for that image may not be freed until the window is destroyed,
or another swapchain is created for the window.
Destroying the swapchain does not invalidate the parent VkSurfaceKHR,
and a new swapchain can be created with it.
When a swapchain associated with a display surface is destroyed, if the image most recently presented to the display surface is from the swapchain being destroyed, then either any display resources modified by presenting images from any swapchain associated with the display surface must be reverted by the implementation to their state prior to the first present performed on one of these swapchains, or such resources must be left in their current state.
If swapchain has exclusive full-screen access, it is released before
the swapchain is destroyed.
To obtain the array of presentable images associated with a swapchain, call:
// Provided by VK_KHR_swapchain
VkResult vkGetSwapchainImagesKHR(
VkDevice device,
VkSwapchainKHR swapchain,
uint32_t* pSwapchainImageCount,
VkImage* pSwapchainImages);-
deviceis the device associated withswapchain. -
swapchainis the swapchain to query. -
pSwapchainImageCountis a pointer to an integer related to the number of presentable images available or queried, as described below. -
pSwapchainImagesis eitherNULLor a pointer to an array ofVkImagehandles.
If pSwapchainImages is NULL, then the number of presentable images
for swapchain is returned in pSwapchainImageCount.
Otherwise, pSwapchainImageCount must point to a variable set by the
user to the number of elements in the pSwapchainImages array, and on
return the variable is overwritten with the number of structures actually
written to pSwapchainImages.
If the value of pSwapchainImageCount is less than the number of
presentable images for swapchain, at most pSwapchainImageCount
structures will be written, and VK_INCOMPLETE will be returned instead
of VK_SUCCESS, to indicate that not all the available presentable
images were returned.
|
Note
By knowing all presentable images used in the swapchain, the application can
create command buffers that reference these images prior to entering its
main rendering loop.
However, command buffers are not allowed to reference presentable images
created with |
Images returned by vkGetSwapchainImagesKHR are fully backed by memory
before they are passed to the application, as if they are each bound
completely and contiguously to a single VkDeviceMemory object
, unless the swapchain is created with the
VK_SWAPCHAIN_CREATE_DEFERRED_MEMORY_ALLOCATION_BIT_EXT flag
.
All presentable images are initially in the VK_IMAGE_LAYOUT_UNDEFINED
layout, thus before using presentable images, the application must
transition them to a valid layout for the intended use.
Further, the lifetime of presentable images is controlled by the implementation, so applications must not destroy a presentable image. See vkDestroySwapchainKHR for further details on the lifetime of presentable images.
Images can also be created by using vkCreateImage with
VkImageSwapchainCreateInfoKHR and bound to swapchain memory using
vkBindImageMemory2 with VkBindImageMemorySwapchainInfoKHR.
These images can be used anywhere swapchain images are used, and are useful
in logical devices with multiple physical devices to create peer memory
bindings of swapchain memory.
These images and bindings have no effect on what memory is presented.
Unlike images retrieved from vkGetSwapchainImagesKHR, these images
must be destroyed with vkDestroyImage.
To acquire an available presentable image to use, and retrieve the index of that image, call:
// Provided by VK_KHR_swapchain
VkResult vkAcquireNextImageKHR(
VkDevice device,
VkSwapchainKHR swapchain,
uint64_t timeout,
VkSemaphore semaphore,
VkFence fence,
uint32_t* pImageIndex);-
deviceis the device associated withswapchain. -
swapchainis the non-retired swapchain from which an image is being acquired. -
timeoutspecifies how long the function waits, in nanoseconds, if no image is available. -
semaphoreis VK_NULL_HANDLE or a semaphore to signal. -
fenceis VK_NULL_HANDLE or a fence to signal. -
pImageIndexis a pointer to auint32_tin which the index of the next image to use (i.e. an index into the array of images returned byvkGetSwapchainImagesKHR) is returned.
If the swapchain has been created with the
VK_SWAPCHAIN_CREATE_DEFERRED_MEMORY_ALLOCATION_BIT_EXT flag, the image
whose index is returned in pImageIndex will be fully backed by memory
before this call returns to the application, as if it is bound completely
and contiguously to a single VkDeviceMemory object.
If an image is acquired successfully, vkAcquireNextImageKHR must
either return VK_SUCCESS or VK_SUBOPTIMAL_KHR.
The implementation may return VK_SUBOPTIMAL_KHR if the swapchain no
longer matches the surface properties exactly, but can still be used for
presentation.
When successful, vkAcquireNextImageKHR acquires a presentable image
from swapchain that an application can use, and sets
pImageIndex to the index of that image within the swapchain.
The presentation engine may not have finished reading from the image at the
time it is acquired, so the application must use semaphore and/or
fence to ensure that the image layout and contents are not modified
until the presentation engine reads have completed.
Once vkAcquireNextImageKHR successfully acquires an image, the
semaphore signal operation referenced by semaphore, if not
VK_NULL_HANDLE, and the fence signal operation referenced by
fence, if not VK_NULL_HANDLE, are submitted for execution.
If vkAcquireNextImageKHR does not successfully acquire an image,
semaphore and fence are unaffected.
The order in which images are acquired is implementation-dependent, and may
be different than the order the images were presented.
If timeout is zero, then vkAcquireNextImageKHR does not wait,
and will either successfully acquire an image, or fail and return
VK_NOT_READY if no image is available.
If the specified timeout period expires before an image is acquired,
vkAcquireNextImageKHR returns VK_TIMEOUT.
If timeout is UINT64_MAX, the timeout period is treated as
infinite, and vkAcquireNextImageKHR will block until an image is
acquired or an error occurs.
Let S be the number of images in swapchain.
If swapchain is created with
VkSwapchainPresentModesCreateInfoEXT, let M be the maximum of
the values in VkSurfaceCapabilitiesKHR::minImageCount when
queried with each present mode in
VkSwapchainPresentModesCreateInfoEXT::pPresentModes in
VkSurfacePresentModeEXT.
Otherwise, let M be the value of
VkSurfaceCapabilitiesKHR::minImageCount without a
VkSurfacePresentModeEXT as part of the query input.
vkAcquireNextImageKHR should not be called if the number of images
that the application has currently acquired is greater than S-M.
If vkAcquireNextImageKHR is called when the number of images that the
application has currently acquired is less than or equal to S-M,
vkAcquireNextImageKHR must return in finite time with an allowed
VkResult code.
|
Note
Returning a result in finite time guarantees that the implementation cannot
deadlock an application, or suspend its execution indefinitely with correct
API usage.
Acquiring too many images at once may block indefinitely, which is covered
by valid usage when attempting to use |
|
Note
|
If the swapchain images no longer match native surface properties, either
VK_SUBOPTIMAL_KHR or VK_ERROR_OUT_OF_DATE_KHR must be returned.
If VK_ERROR_OUT_OF_DATE_KHR is returned, no image is acquired and
attempts to present previously acquired images to the swapchain will also
fail with VK_ERROR_OUT_OF_DATE_KHR.
Applications need to create a new swapchain for the surface to continue
presenting if VK_ERROR_OUT_OF_DATE_KHR is returned.
If device loss occurs (see Lost Device) before
the timeout has expired, vkAcquireNextImageKHR must return in finite
time with either one of the allowed success codes, or
VK_ERROR_DEVICE_LOST.
If semaphore is not VK_NULL_HANDLE, the semaphore must be
unsignaled, with no signal or wait operations pending.
It will become signaled when the application can use the image.
|
Note
Use of |
If fence is not equal to VK_NULL_HANDLE, the fence must be
unsignaled, with no signal operations pending.
It will become signaled when the application can use the image.
|
Note
Applications should not rely on |
An application must wait until either the semaphore or fence is
signaled before accessing the image’s data.
|
Note
When the presentable image will be accessed by some stage S, the recommended idiom for ensuring correct synchronization is:
|
After a successful return, the image indicated by pImageIndex and its
data will be unmodified compared to when it was presented.
|
Note
Exclusive ownership of presentable images corresponding to a swapchain
created with |
The possible return values for vkAcquireNextImageKHR depend on the
timeout provided:
-
VK_SUCCESSis returned if an image became available. -
VK_ERROR_SURFACE_LOST_KHRis returned if the surface becomes no longer available. -
VK_NOT_READYis returned iftimeoutis zero and no image was available. -
VK_TIMEOUTis returned iftimeoutis greater than zero and less thanUINT64_MAX, and no image became available within the time allowed. -
VK_SUBOPTIMAL_KHRis returned if an image became available, and the swapchain no longer matches the surface properties exactly, but can still be used to present to the surface successfully.
|
Note
This may happen, for example, if the platform surface has been resized but the platform is able to scale the presented images to the new size to produce valid surface updates. It is up to the application to decide whether it prefers to continue using the current swapchain indefinitely or temporarily in this state, or to re-create the swapchain to better match the platform surface properties. |
-
VK_ERROR_OUT_OF_DATE_KHRis returned if the surface has changed in such a way that it is no longer compatible with the swapchain, and further presentation requests using the swapchain will fail. Applications must query the new surface properties and recreate their swapchain if they wish to continue presenting to the surface.
If the native surface and presented image sizes no longer match,
presentation may fail
unless the swapchain is created with a non-zero value in
VkSwapchainPresentScalingCreateInfoEXT::scalingBehavior
.
If presentation does succeed, the mapping from the presented image to the
native surface is
defined by the VkSwapchainPresentScalingCreateInfoEXT structure if
provided.
Otherwise it is
implementation-defined.
It is the application’s responsibility to detect surface size changes and
react appropriately.
If presentation fails because of a mismatch in the surface and presented
image sizes, a VK_ERROR_OUT_OF_DATE_KHR error will be returned.
|
Note
For example, consider a 4x3 window/surface that gets resized to be 3x4 (taller than wider). On some window systems, the portion of the window/surface that was previously and still is visible (the 3x3 part) will contain the same contents as before, while the remaining parts of the window will have undefined contents. Other window systems may squash/stretch the image to fill the new window size without any undefined contents, or apply some other mapping. |
To acquire an available presentable image to use, and retrieve the index of that image, call:
// Provided by VK_VERSION_1_1 with VK_KHR_swapchain, VK_KHR_device_group with VK_KHR_swapchain
VkResult vkAcquireNextImage2KHR(
VkDevice device,
const VkAcquireNextImageInfoKHR* pAcquireInfo,
uint32_t* pImageIndex);-
deviceis the device associated withswapchain. -
pAcquireInfois a pointer to a VkAcquireNextImageInfoKHR structure containing parameters of the acquire. -
pImageIndexis a pointer to auint32_tthat is set to the index of the next image to use.
If the swapchain has been created with the
VK_SWAPCHAIN_CREATE_DEFERRED_MEMORY_ALLOCATION_BIT_EXT flag, the image
whose index is returned in pImageIndex will be fully backed by memory
before this call returns to the application.
The VkAcquireNextImageInfoKHR structure is defined as:
// Provided by VK_VERSION_1_1 with VK_KHR_swapchain, VK_KHR_device_group with VK_KHR_swapchain
typedef struct VkAcquireNextImageInfoKHR {
VkStructureType sType;
const void* pNext;
VkSwapchainKHR swapchain;
uint64_t timeout;
VkSemaphore semaphore;
VkFence fence;
uint32_t deviceMask;
} VkAcquireNextImageInfoKHR;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
swapchainis a non-retired swapchain from which an image is acquired. -
timeoutspecifies how long the function waits, in nanoseconds, if no image is available. -
semaphoreis VK_NULL_HANDLE or a semaphore to signal. -
fenceis VK_NULL_HANDLE or a fence to signal. -
deviceMaskis a mask of physical devices for which the swapchain image will be ready to use when the semaphore or fence is signaled.
If vkAcquireNextImageKHR is used, the device mask is considered to include all physical devices in the logical device.
|
Note
vkAcquireNextImage2KHR signals at most one semaphore, even if the
application requests waiting for multiple physical devices to be ready via
the |
After queueing all rendering commands and transitioning the image to the correct layout, to queue an image for presentation, call:
// Provided by VK_KHR_swapchain
VkResult vkQueuePresentKHR(
VkQueue queue,
const VkPresentInfoKHR* pPresentInfo);-
queueis a queue that is capable of presentation to the target surface’s platform on the same device as the image’s swapchain. -
pPresentInfois a pointer to a VkPresentInfoKHR structure specifying parameters of the presentation.
|
Note
There is no requirement for an application to present images in the same order that they were acquired - applications can arbitrarily present any image that is currently acquired. |
Any writes to memory backing the images referenced by the
pImageIndices and pSwapchains members of pPresentInfo,
that are available before vkQueuePresentKHR is executed, are
automatically made visible to the read access performed by the presentation
engine.
This automatic visibility operation for an image happens-after the semaphore
signal operation, and happens-before the presentation engine accesses the
image.
Queueing an image for presentation defines a set of queue operations, including waiting on the semaphores and submitting a presentation request to the presentation engine. However, the scope of this set of queue operations does not include the actual processing of the image by the presentation engine.
|
Note
The origin of the native orientation of the surface coordinate system is not
specified in the Vulkan specification; it depends on the platform.
For most platforms the origin is by default upper-left, meaning the pixel of
the presented VkImage at coordinates (0,0) would appear at the
upper left pixel of the platform surface (assuming
|
If vkQueuePresentKHR fails to enqueue the corresponding set of queue
operations, it may return VK_ERROR_OUT_OF_HOST_MEMORY or
VK_ERROR_OUT_OF_DEVICE_MEMORY.
If it does, the implementation must ensure that the state and contents of
any resources or synchronization primitives referenced is unaffected by the
call or its failure.
If vkQueuePresentKHR fails in such a way that the implementation is
unable to make that guarantee, the implementation must return
VK_ERROR_DEVICE_LOST.
However, if the presentation request is rejected by the presentation engine
with an error VK_ERROR_OUT_OF_DATE_KHR,
VK_ERROR_FULL_SCREEN_EXCLUSIVE_MODE_LOST_EXT,
or VK_ERROR_SURFACE_LOST_KHR, the set of queue operations are still
considered to be enqueued and thus any semaphore wait operation specified in
VkPresentInfoKHR will execute when the corresponding queue operation
is complete.
Calls to vkQueuePresentKHR may block, but must return in finite
time.
If any swapchain member of pPresentInfo was created with
VK_FULL_SCREEN_EXCLUSIVE_APPLICATION_CONTROLLED_EXT,
VK_ERROR_FULL_SCREEN_EXCLUSIVE_MODE_LOST_EXT will be returned if that
swapchain does not have exclusive full-screen access, possibly for
implementation-specific reasons outside of the application’s control.
For any pSwapchains member of pPresentInfo, if that swapchain has
enabled the collection of presentation timings via
vkSetSwapchainTimingEXT, one entry of its internal timing queue is
reserved until the results have been collected by
vkGetPastPresentationTimingEXT.
VK_ERROR_PRESENT_TIMING_QUEUE_FULL_EXT is returned if a swapchain is
unable to reserve an entry in its queue.
The VkPresentInfoKHR structure is defined as:
// Provided by VK_KHR_swapchain
typedef struct VkPresentInfoKHR {
VkStructureType sType;
const void* pNext;
uint32_t waitSemaphoreCount;
const VkSemaphore* pWaitSemaphores;
uint32_t swapchainCount;
const VkSwapchainKHR* pSwapchains;
const uint32_t* pImageIndices;
VkResult* pResults;
} VkPresentInfoKHR;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
waitSemaphoreCountis the number of semaphores to wait for before issuing the present request. The number may be zero. -
pWaitSemaphoresisNULLor a pointer to an array of VkSemaphore objects withwaitSemaphoreCountentries, and specifies the semaphores to wait for before issuing the present request. -
swapchainCountis the number of swapchains being presented to by this command. -
pSwapchainsis a pointer to an array of VkSwapchainKHR objects withswapchainCountentries. -
pImageIndicesis a pointer to an array of indices into the array of each swapchain’s presentable images, withswapchainCountentries. Each entry in this array identifies the image to present on the corresponding entry in thepSwapchainsarray. -
pResultsis a pointer to an array of VkResult typed elements withswapchainCountentries. Applications that do not need per-swapchain results can useNULLforpResults. If non-NULL, each entry inpResultswill be set to the VkResult for presenting the swapchain corresponding to the same index inpSwapchains.
Before an application can present an image, the image’s layout must be
transitioned to the VK_IMAGE_LAYOUT_PRESENT_SRC_KHR
layout, or for a shared presentable image the
VK_IMAGE_LAYOUT_SHARED_PRESENT_KHR
layout.
|
Note
When transitioning the image to
|
When the VK_KHR_incremental_present extension is enabled,
additional fields can be specified that allow an application to specify
that only certain rectangular regions of the presentable images of a
swapchain are changed.
This is an optimization hint that a presentation engine may use to only
update the region of a surface that is actually changing.
The application still must ensure that all pixels of a presented image
contain the desired values, in case the presentation engine ignores this
hint.
An application can provide this hint by adding a VkPresentRegionsKHR
structure to the pNext chain of the VkPresentInfoKHR structure.
The VkPresentRegionsKHR structure is defined as:
// Provided by VK_KHR_incremental_present
typedef struct VkPresentRegionsKHR {
VkStructureType sType;
const void* pNext;
uint32_t swapchainCount;
const VkPresentRegionKHR* pRegions;
} VkPresentRegionsKHR;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
swapchainCountis the number of swapchains being presented to by this command. -
pRegionsisNULLor a pointer to an array ofVkPresentRegionKHRelements withswapchainCountentries. If notNULL, each element ofpRegionscontains the region that has changed since the last present to the swapchain in the corresponding entry in theVkPresentInfoKHR::pSwapchainsarray.
For a given image and swapchain, the region to present is specified by the
VkPresentRegionKHR structure, which is defined as:
// Provided by VK_KHR_incremental_present
typedef struct VkPresentRegionKHR {
uint32_t rectangleCount;
const VkRectLayerKHR* pRectangles;
} VkPresentRegionKHR;-
rectangleCountis the number of rectangles inpRectangles, or zero if the entire image has changed and should be presented. -
pRectanglesis eitherNULLor a pointer to an array ofVkRectLayerKHRstructures. TheVkRectLayerKHRstructure is the framebuffer coordinates, plus layer, of a portion of a presentable image that has changed and must be presented. If non-NULL, each entry inpRectanglesis a rectangle of the given image that has changed since the last image was presented to the given swapchain. The rectangles must be specified relative to VkSurfaceCapabilitiesKHR::currentTransform, regardless of the swapchain’spreTransform. The presentation engine will apply thepreTransformtransformation to the rectangles, along with any further transformation it applies to the image content.
The VkRectLayerKHR structure is defined as:
// Provided by VK_KHR_incremental_present
typedef struct VkRectLayerKHR {
VkOffset2D offset;
VkExtent2D extent;
uint32_t layer;
} VkRectLayerKHR;-
offsetis the origin of the rectangle, in pixels. -
extentis the size of the rectangle, in pixels. -
layeris the layer of the image. For images with only one layer, the value oflayermust be 0.
Some platforms allow the size of a surface to change, and then scale the
pixels of the image to fit the surface.
VkRectLayerKHR specifies pixels of the swapchain’s image(s), which
will be constant for the life of the swapchain.
When the VK_KHR_display_swapchain extension is enabled, additional
fields can be specified when presenting an image to a swapchain by setting
VkPresentInfoKHR::pNext to point to a
VkDisplayPresentInfoKHR structure.
The VkDisplayPresentInfoKHR structure is defined as:
// Provided by VK_KHR_display_swapchain
typedef struct VkDisplayPresentInfoKHR {
VkStructureType sType;
const void* pNext;
VkRect2D srcRect;
VkRect2D dstRect;
VkBool32 persistent;
} VkDisplayPresentInfoKHR;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
srcRectis a rectangular region of pixels to present. It must be a subset of the image being presented. IfVkDisplayPresentInfoKHRis not specified, this region will be assumed to be the entire presentable image. -
dstRectis a rectangular region within the visible region of the swapchain’s display mode. IfVkDisplayPresentInfoKHRis not specified, this region will be assumed to be the entire visible region of the swapchain’s mode. If the specified rectangle is a subset of the display mode’s visible region, content from display planes below the swapchain’s plane will be visible outside the rectangle. If there are no planes below the swapchain’s, the area outside the specified rectangle will be black. If portions of the specified rectangle are outside of the display’s visible region, pixels mapping only to those portions of the rectangle will be discarded. -
persistent: If this isVK_TRUE, the display engine will enable buffered mode on displays that support it. This allows the display engine to stop sending content to the display until a new image is presented. The display will instead maintain a copy of the last presented image. This allows less power to be used, but may increase presentation latency. IfVkDisplayPresentInfoKHRis not specified, persistent mode will not be used.
If the extent of the srcRect and dstRect are not equal, the
presented pixels will be scaled accordingly.
If the pNext chain of VkPresentInfoKHR includes a
VkDeviceGroupPresentInfoKHR structure, then that structure includes an
array of device masks and a device group present mode.
The VkDeviceGroupPresentInfoKHR structure is defined as:
// Provided by VK_VERSION_1_1 with VK_KHR_swapchain, VK_KHR_device_group with VK_KHR_swapchain
typedef struct VkDeviceGroupPresentInfoKHR {
VkStructureType sType;
const void* pNext;
uint32_t swapchainCount;
const uint32_t* pDeviceMasks;
VkDeviceGroupPresentModeFlagBitsKHR mode;
} VkDeviceGroupPresentInfoKHR;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
swapchainCountis zero or the number of elements inpDeviceMasks. -
pDeviceMasksis a pointer to an array of device masks, one for each element of VkPresentInfoKHR::pSwapchains. -
modeis a VkDeviceGroupPresentModeFlagBitsKHR value specifying the device group present mode that will be used for this present.
If mode is VK_DEVICE_GROUP_PRESENT_MODE_LOCAL_BIT_KHR, then each
element of pDeviceMasks selects which instance of the swapchain image
is presented.
Each element of pDeviceMasks must have exactly one bit set, and the
corresponding physical device must have a presentation engine as reported
by VkDeviceGroupPresentCapabilitiesKHR.
If mode is VK_DEVICE_GROUP_PRESENT_MODE_REMOTE_BIT_KHR, then
each element of pDeviceMasks selects which instance of the swapchain
image is presented.
Each element of pDeviceMasks must have exactly one bit set, and some
physical device in the logical device must include that bit in its
VkDeviceGroupPresentCapabilitiesKHR::presentMask.
If mode is VK_DEVICE_GROUP_PRESENT_MODE_SUM_BIT_KHR, then each
element of pDeviceMasks selects which instances of the swapchain image
are component-wise summed and the sum of those images is presented.
If the sum in any component is outside the representable range, the value of
that component is undefined.
Each element of pDeviceMasks must have a value for which all set bits
are set in one of the elements of
VkDeviceGroupPresentCapabilitiesKHR::presentMask.
If mode is
VK_DEVICE_GROUP_PRESENT_MODE_LOCAL_MULTI_DEVICE_BIT_KHR, then each
element of pDeviceMasks selects which instance(s) of the swapchain
images are presented.
For each bit set in each element of pDeviceMasks, the corresponding
physical device must have a presentation engine as reported by
VkDeviceGroupPresentCapabilitiesKHR.
If VkDeviceGroupPresentInfoKHR is not provided or swapchainCount
is zero then the masks are considered to be 1.
If VkDeviceGroupPresentInfoKHR is not provided, mode is
considered to be VK_DEVICE_GROUP_PRESENT_MODE_LOCAL_BIT_KHR.
When the presentAtAbsoluteTime or
presentAtRelativeTime feature is
enabled, additional fields can be specified that allow an application to
specify the earliest time that an image should be displayed.
This allows an application to avoid stutter that is caused by an image being
displayed earlier than planned.
Such stuttering might occur with both fixed and variable-refresh-rate
displays, because stuttering occurs when the geometry is not correctly
positioned for when the image is displayed.
An application can instruct the presentation engine that an image must
not be displayed earlier than a specified time by including the
VkPresentTimesInfoEXT structure in the pNext chain of the
VkPresentInfoKHR structure.
The VkPresentTimesInfoEXT structure is defined as:
// Provided by VK_EXT_present_timing
typedef struct VkPresentTimesInfoEXT {
VkStructureType sType;
const void* pNext;
uint32_t swapchainCount;
const VkPresentTimeEXT* pTimes;
} VkPresentTimesInfoEXT;-
sTypeis the type of this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
swapchainCountis the number of swapchains being presented to by this command. -
pTimesisNULLor a pointer to an array ofVkPresentTimeEXTelements withswapchainCountentries. If notNULL, each element ofpTimescontains the earliest present time or the minimum present duration for the image corresponding to the entry in theVkPresentInfoKHR::pImageIndicesarray.
The semantics of a specified target present time or duration only apply to the following present modes:
-
VK_PRESENT_MODE_FIFO_KHR. Tearing cannot be observed. The first queued image is dequeued and presented if both: 1) its associated wait semaphore(s) have signaled, and 2) its target present time is less-than or equal-to the current time. -
VK_PRESENT_MODE_FIFO_RELAXED_KHR. For images that are presented in time to be displayed at the next vertical blanking period, the semantics are identical as forVK_PRESENT_MODE_FIFO_KHR. For images that are presented late, and are displayed after the start of the vertical blanking period (i.e. with tearing), the values ofVkPastPresentationTimingEXTmay be treated as if the image was displayed at the start of the vertical blanking period, or may be treated the same as forVK_PRESENT_MODE_IMMEDIATE_KHR.
The VkPresentTimeEXT union is defined as:
// Provided by VK_EXT_present_timing
typedef union VkPresentTimeEXT {
uint64_t targetPresentTime;
uint64_t minPresentDuration;
} VkPresentTimeEXT;-
targetPresentTime, if non-zero, specifies the earliest time the application wants the image to complete the swapchain’s target present stage. A value of zero specifies that the presentation engine may display the image at any time allowed by the current present mode. -
minPresentDuration, if non-zero, specifies the minimum duration in nanoseconds before which the next image presentation request can reach the target present stage. A value of zero specifies that the presentation engine may display the image for any duration allowed by the current present mode.
The contents of the VkPresentTimeEXT union is interpreted depending on
the associated VkPresentInfoKHR::pSwapchains member creation
values. If
VkSwapchainPresentTimingCreateInfoEXT::presentAtRelativeTime was
VK_FALSE when creating the swapchain, targetPresentTime is
used. Otherwise, minPresentDuration is used.
targetPresentTime is a time in nanoseconds, according to the
time-domain being used. The presentation engine must not complete the
target present stage, specified in the associated swapchain
VkSwapchainPresentTimingCreateInfoEXT::presentStageTarget, at an
earlier time.
|
Note
Applications that use |
The VkPresentStageTimeEXT structure is defined as:
// Provided by VK_EXT_present_timing
typedef struct VkPresentStageTimeEXT {
VkPresentStageFlagsEXT stage;
uint64_t time;
} VkPresentStageTimeEXT;-
stageis a VkPresentStageFlagsEXT value specifying a present stage. -
timeis a time in nanoseconds associated with thestage.
Presenting an image to the user typically involves multiple stages. Bits which can be set to specify present stages are:
// Provided by VK_EXT_present_timing
typedef enum VkPresentStageFlagBitsEXT {
VK_PRESENT_STAGE_IMAGE_HANDOFF_BIT_EXT = 0x00000001,
VK_PRESENT_STAGE_IMAGE_LATCHED_BIT_EXT = 0x00000002,
VK_PRESENT_STAGE_IMAGE_FIRST_PIXEL_OUT_BIT_EXT = 0x00000004,
VK_PRESENT_STAGE_IMAGE_FIRST_PIXEL_VISIBLE_BIT_EXT = 0x00000008,
} VkPresentStageFlagBitsEXT;-
VK_PRESENT_STAGE_IMAGE_HANDOFF_BIT_EXTis the stage after which the presentation request of the image has been passed to a system-specific entity of the presentation engine that is outside the control of the Vulkan implementation. This stage is the onlyVkPresentStageFlagBitsEXTthat is required to be supported. -
VK_PRESENT_STAGE_IMAGE_LATCHED_BIT_EXTis the stage after which the image associated with the presentation request has been latched by the presentation engine to create the presentation of a future refresh cycle. -
VK_PRESENT_STAGE_IMAGE_FIRST_PIXEL_OUT_BIT_EXTis the stage after which data for the first pixel of the presentation request associated with the image has left the presentation engine for a display hardware. -
VK_PRESENT_STAGE_IMAGE_FIRST_PIXEL_VISIBLE_BIT_EXTis the stage after which a display hardware has made the first pixel visible for the presentation request associated with the image to be presented.
// Provided by VK_EXT_present_timing
typedef VkFlags VkPresentStageFlagsEXT;VkPresentStageFlagsEXT is a bitmask type for setting a mask of zero or
more VkPresentStageFlagBitsEXT.
When the VK_GOOGLE_display_timing extension is enabled, additional
fields can be specified that allow an application to specify the earliest
time that an image should be displayed.
This allows an application to avoid stutter that is caused by an image being
displayed earlier than planned.
Such stuttering can occur with both fixed and variable-refresh-rate
displays, because stuttering occurs when the geometry is not correctly
positioned for when the image is displayed.
An application can instruct the presentation engine that an image should
not be displayed earlier than a specified time by adding a
VkPresentTimesInfoGOOGLE structure to the pNext chain of the
VkPresentInfoKHR structure.
The VkPresentTimesInfoGOOGLE structure is defined as:
// Provided by VK_GOOGLE_display_timing
typedef struct VkPresentTimesInfoGOOGLE {
VkStructureType sType;
const void* pNext;
uint32_t swapchainCount;
const VkPresentTimeGOOGLE* pTimes;
} VkPresentTimesInfoGOOGLE;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
swapchainCountis the number of swapchains being presented to by this command. -
pTimesisNULLor a pointer to an array ofVkPresentTimeGOOGLEelements withswapchainCountentries. If notNULL, each element ofpTimescontains the earliest time to present the image corresponding to the entry in theVkPresentInfoKHR::pImageIndicesarray.
The VkPresentTimeGOOGLE structure is defined as:
// Provided by VK_GOOGLE_display_timing
typedef struct VkPresentTimeGOOGLE {
uint32_t presentID;
uint64_t desiredPresentTime;
} VkPresentTimeGOOGLE;-
presentIDis an application-provided identification value, that can be used with the results of vkGetPastPresentationTimingGOOGLE, in order to uniquely identify this present. In order to be useful to the application, it should be unique within some period of time that is meaningful to the application. -
desiredPresentTimespecifies that the image given should not be displayed to the user any earlier than this time.desiredPresentTimeis a time in nanoseconds, relative to a monotonically-increasing clock (e.g.CLOCK_MONOTONIC(see clock_gettime(2)) on Android and Linux). A value of zero specifies that the presentation engine may display the image at any time. This is useful when the application desires to providepresentID, but does not need a specificdesiredPresentTime.
The VkPresentIdKHR structure is defined as:
// Provided by VK_KHR_present_id
typedef struct VkPresentIdKHR {
VkStructureType sType;
const void* pNext;
uint32_t swapchainCount;
const uint64_t* pPresentIds;
} VkPresentIdKHR;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
swapchainCountis the number of swapchains being presented to thevkQueuePresentKHRcommand. -
pPresentIdsisNULLor a pointer to an array ofuint64_twithswapchainCountentries. If notNULL, each non-zero value inpPresentIdsspecifies the present id to be associated with the presentation of the swapchain with the same index in the vkQueuePresentKHR call.
For applications to be able to reference specific presentation events queued
by a call to vkQueuePresentKHR, an identifier needs to be associated
with them.
When the presentId feature is enabled,
applications can include the VkPresentIdKHR structure in the
pNext chain of the VkPresentInfoKHR structure to supply
identifiers.
Each VkSwapchainKHR has a presentId associated with it.
This value is initially set to zero when the VkSwapchainKHR is
created.
When a VkPresentIdKHR structure with a non-NULL pPresentIds is
included in the pNext chain of a VkPresentInfoKHR structure,
each pSwapchains entry has a presentId associated in the
pPresentIds array at the same index as the swapchain in the
pSwapchains array.
If this presentId is non-zero, then the application can later use this
value to refer to that image presentation.
A value of zero indicates that this presentation has no associated
presentId.
A non-zero presentId must be greater than any non-zero presentId passed
previously by the application for the same swapchain.
There is no requirement for any precise timing relationship between the presentation of the image to the user and the update of the presentId value, but implementations should make this as close as possible to the presentation of the first pixel in the new image to the user.
When the presentWait feature is enabled, an
application can wait for an image to be presented to the user by first
specifying a presentId for the target presentation by adding a
VkPresentIdKHR structure to the pNext chain of the
VkPresentInfoKHR structure and then waiting for that presentation to
complete by calling:
// Provided by VK_KHR_present_wait
VkResult vkWaitForPresentKHR(
VkDevice device,
VkSwapchainKHR swapchain,
uint64_t presentId,
uint64_t timeout);-
deviceis the device associated withswapchain. -
swapchainis the non-retired swapchain on which an image was queued for presentation. -
presentIdis the presentation presentId to wait for. -
timeoutis the timeout period in units of nanoseconds.timeoutis adjusted to the closest value allowed by the implementation-dependent timeout accuracy, which may be substantially longer than one nanosecond, and may be longer than the requested period.
vkWaitForPresentKHR waits for the presentId associated with
swapchain to be increased in value so that it is at least equal to
presentId.
For VK_PRESENT_MODE_MAILBOX_KHR (or other present mode where images
may be replaced in the presentation queue) any wait of this type associated
with such an image must be signaled no later than a wait associated with
the replacing image would be signaled.
When the presentation has completed, the presentId associated with the
related pSwapchains entry will be increased in value so that it is at
least equal to the value provided in the VkPresentIdKHR structure.
There is no requirement for any precise timing relationship between the presentation of the image to the user and the update of the presentId value, but implementations should make this as close as possible to the presentation of the first pixel in the next image being presented to the user.
The call to vkWaitForPresentKHR will block until either the presentId
associated with swapchain is greater than or equal to presentId,
or timeout nanoseconds passes.
When the swapchain becomes OUT_OF_DATE, the call will either return
VK_SUCCESS (if the image was delivered to the presentation engine and
may have been presented to the user) or will return early with status
VK_ERROR_OUT_OF_DATE_KHR (if the image was not presented to the user).
As an exception to the normal rules for objects which are externally
synchronized, the swapchain passed to vkWaitForPresentKHR may
be simultaneously used by other threads in calls to functions other than
vkDestroySwapchainKHR.
Access to the swapchain data associated with this extension must be atomic
within the implementation.
When the VK_GGP_frame_token extension is enabled, a Google Games
Platform frame token can be specified when presenting an image to a
swapchain by adding a VkPresentFrameTokenGGP structure to the
pNext chain of the VkPresentInfoKHR structure.
The VkPresentFrameTokenGGP structure is defined as:
// Provided by VK_GGP_frame_token
typedef struct VkPresentFrameTokenGGP {
VkStructureType sType;
const void* pNext;
GgpFrameToken frameToken;
} VkPresentFrameTokenGGP;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
frameTokenis the Google Games Platform frame token.
The VkSwapchainPresentModeInfoEXT structure is defined as:
// Provided by VK_EXT_swapchain_maintenance1
typedef struct VkSwapchainPresentModeInfoEXT {
VkStructureType sType;
const void* pNext;
uint32_t swapchainCount;
const VkPresentModeKHR* pPresentModes;
} VkSwapchainPresentModeInfoEXT;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
swapchainCountis the number of swapchains being presented to by this command. -
pPresentModesis a list of presentation modes withswapchainCountentries.
If the pNext chain of VkPresentInfoKHR includes a
VkSwapchainPresentModeInfoEXT structure, then that structure defines
the presentation modes used for the current and subsequent presentation
operations.
When the application changes present modes with VkSwapchainPresentModeInfoEXT, images that have already been queued for presentation will continue to be presented according to the previous present mode. The current image being queued for presentation and subsequent images will be presented according to the new present mode. The behavior during the transition between the two modes is defined as follows.
-
Transition from
VK_PRESENT_MODE_SHARED_CONTINUOUS_REFRESH_KHRtoVK_PRESENT_MODE_SHARED_DEMAND_REFRESH_KHR: the presentation engine updates the shared presentable image according to the behavior ofVK_PRESENT_MODE_SHARED_DEMAND_REFRESH_KHR. -
Transition from
VK_PRESENT_MODE_SHARED_DEMAND_REFRESH_KHRtoVK_PRESENT_MODE_SHARED_CONTINUOUS_REFRESH_KHR: the presentation engine may update the shared presentable image or defer that to its regular refresh cycle, according to the behavior ofVK_PRESENT_MODE_SHARED_CONTINUOUS_REFRESH_KHR. -
Transition between
VK_PRESENT_MODE_FIFO_KHRandVK_PRESENT_MODE_FIFO_RELAXED_KHR: Images continue to be appended to the same FIFO queue, and the behavior with respect to waiting for vertical blanking period will follow the new mode for current and subsequent images. -
Transition from
VK_PRESENT_MODE_IMMEDIATE_KHRtoVK_PRESENT_MODE_FIFO_KHRorVK_PRESENT_MODE_FIFO_RELAXED_KHR: As all prior present requests in theVK_PRESENT_MODE_IMMEDIATE_KHRmode are applied immediately, there are no outstanding present operations in this mode, and current and subsequent images are appended to the FIFO queue and presented according to the new mode. -
Transition from
VK_PRESENT_MODE_MAILBOX_KHRtoVK_PRESENT_MODE_FIFO_KHRorVK_PRESENT_MODE_FIFO_RELAXED_KHR: Presentation in both modes require waiting for the next vertical blanking period, withVK_PRESENT_MODE_MAILBOX_KHRallowing the pending present operation to be replaced by a new one. In this case, the current present operation will replace the pending present operation and is applied according to the new mode. -
Transition from
VK_PRESENT_MODE_FIFO_KHRorVK_PRESENT_MODE_FIFO_RELAXED_KHRtoVK_PRESENT_MODE_IMMEDIATE_KHRorVK_PRESENT_MODE_MAILBOX_KHR: If the FIFO queue is empty, presentation is done according to the behavior of the new mode. If there are present operations in the FIFO queue, once the last present operation is performed based on the respective vertical blanking period, the current and subsequent updates are applied according to the new mode. -
The behavior during transition between any other present modes, if possible, is implementation defined.
The VkSwapchainPresentFenceInfoEXT structure is defined as:
// Provided by VK_EXT_swapchain_maintenance1
typedef struct VkSwapchainPresentFenceInfoEXT {
VkStructureType sType;
const void* pNext;
uint32_t swapchainCount;
const VkFence* pFences;
} VkSwapchainPresentFenceInfoEXT;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
swapchainCountis the number of swapchains being presented to by this command. -
pFencesis a list of fences withswapchainCountentries. Each entry must be VK_NULL_HANDLE or the handle of a fence to signal when the relevant operations on the associated swapchain have completed.
The set of queue operations defined by queuing an image for presentation, as well as operations performed by the presentation engine access the payloads of objects associated with the presentation operation. The associated objects include:
-
The swapchain image, its implicitly bound memory, and any other resources bound to that memory.
-
The wait semaphores specified when queuing the image for presentation.
The application can provide a fence that the implementation will signal when all such queue operations have completed and the presentation engine has taken a reference to the payload of any objects it accesses as part of the present operation. For all binary wait semaphores imported by the presentation engine using the equivalent of reference transference, as described in Importing Semaphore Payloads, this fence must not signal until all such semaphore payloads have been reset by the presentation engine.
The application can destroy the wait semaphores associated with a given presentation operation when at least one of the associated fences is signaled, and can destroy the swapchain when the fences associated with all past presentation requests referring to that swapchain have signaled.
Fences associated with presentations to the same swapchain on the same VkQueue must be signaled in the same order as the present operations.
To specify a fence for each swapchain in a present operation, include the
VkSwapchainPresentFenceInfoEXT structure in the pNext chain of
the VkPresentInfoKHR structure.
vkQueuePresentKHR releases the acquisition of the images referenced by
imageIndices.
The queue family corresponding to the queue vkQueuePresentKHR is
executed on must have ownership of the presented images as defined in
Resource Sharing.
vkQueuePresentKHR does not alter the queue family ownership, but the
presented images must not be used again before they have been reacquired
using vkAcquireNextImageKHR.
The processing of the presentation happens in issue order with other queue operations, but semaphores have to be used to ensure that prior rendering and other commands in the specified queue complete before the presentation begins. The presentation command itself does not delay processing of subsequent commands on the queue, however, presentation requests sent to a particular queue are always performed in order. Exact presentation timing is controlled by the semantics of the presentation engine and native platform in use.
If an image is presented to a swapchain created from a display surface, the mode of the associated display will be updated, if necessary, to match the mode specified when creating the display surface. The mode switch and presentation of the specified image will be performed as one atomic operation.
The result codes VK_ERROR_OUT_OF_DATE_KHR and VK_SUBOPTIMAL_KHR
have the same meaning when returned by vkQueuePresentKHR as they do
when returned by vkAcquireNextImageKHR.
If multiple swapchains are presented, the result code is determined applying
the following rules in order:
-
If the device is lost,
VK_ERROR_DEVICE_LOSTis returned. -
If any of the target surfaces are no longer available the error
VK_ERROR_SURFACE_LOST_KHRis returned. -
If any of the presents would have a result of
VK_ERROR_OUT_OF_DATE_KHRif issued separately thenVK_ERROR_OUT_OF_DATE_KHRis returned. -
If any of the presents would have a result of
VK_ERROR_PRESENT_TIMING_QUEUE_FULL_EXTif issued separately thenVK_ERROR_PRESENT_TIMING_QUEUE_FULL_EXTis returned. -
If any of the presents would have a result of
VK_ERROR_FULL_SCREEN_EXCLUSIVE_MODE_LOST_EXTif issued separately thenVK_ERROR_FULL_SCREEN_EXCLUSIVE_MODE_LOST_EXTis returned. -
If any of the presents would have a result of
VK_SUBOPTIMAL_KHRif issued separately thenVK_SUBOPTIMAL_KHRis returned. -
Otherwise
VK_SUCCESSis returned.
Presentation is a read-only operation that will not affect the content of
the presentable images.
Upon reacquiring the image and transitioning it away from the
VK_IMAGE_LAYOUT_PRESENT_SRC_KHR layout, the contents will be the same
as they were prior to transitioning the image to the present source layout
and presenting it.
However, if a mechanism other than Vulkan is used to modify the platform
window associated with the swapchain, the content of all presentable images
in the swapchain becomes undefined.
|
Note
The application can continue to present any acquired images from a retired
swapchain as long as the swapchain has not entered a state that causes
vkQueuePresentKHR to return |
To release images previously acquired through vkAcquireNextImage2KHR or vkAcquireNextImageKHR, call:
// Provided by VK_EXT_swapchain_maintenance1
VkResult vkReleaseSwapchainImagesEXT(
VkDevice device,
const VkReleaseSwapchainImagesInfoEXT* pReleaseInfo);-
deviceis the device associated with VkReleaseSwapchainImagesInfoEXT::swapchain. -
pReleaseInfois a pointer to a VkReleaseSwapchainImagesInfoEXT structure containing parameters of the release.
Only images that are not in use by the device can be released.
Releasing images is a read-only operation that will not affect the content of the released images. Upon reacquiring the image, the image contents and its layout will be the same as they were prior to releasing it. However, if a mechanism other than Vulkan is used to modify the platform window associated with the swapchain, the content of all presentable images in the swapchain becomes undefined.
|
Note
This functionality is useful during swapchain recreation, where acquired images from the old swapchain can be released instead of presented. |
The VkReleaseSwapchainImagesInfoEXT structure is defined as:
// Provided by VK_EXT_swapchain_maintenance1
typedef struct VkReleaseSwapchainImagesInfoEXT {
VkStructureType sType;
const void* pNext;
VkSwapchainKHR swapchain;
uint32_t imageIndexCount;
const uint32_t* pImageIndices;
} VkReleaseSwapchainImagesInfoEXT;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
swapchainis a swapchain to which images are being released. -
imageIndexCountis the number of image indices to be released. -
pImageIndicesis a pointer to an array of indices into the array ofswapchain’s presentable images, withimageIndexCountentries.
34.11. Hdr Metadata
This section describes how to improve color reproduction of content to better reproduce colors as seen on the reference monitor. Definitions below are from the associated SMPTE 2086, CTA 861.3 and CIE 15:2004 specifications.
To provide Hdr metadata to an implementation, call:
// Provided by VK_EXT_hdr_metadata
void vkSetHdrMetadataEXT(
VkDevice device,
uint32_t swapchainCount,
const VkSwapchainKHR* pSwapchains,
const VkHdrMetadataEXT* pMetadata);-
deviceis the logical device where the swapchain(s) were created. -
swapchainCountis the number of swapchains included inpSwapchains. -
pSwapchainsis a pointer to an array ofswapchainCountVkSwapchainKHR handles. -
pMetadatais a pointer to an array ofswapchainCountVkHdrMetadataEXT structures.
The metadata will be applied to the specified VkSwapchainKHR objects
at the next vkQueuePresentKHR call using that VkSwapchainKHR
object.
The metadata will persist until a subsequent vkSetHdrMetadataEXT
changes it.
The VkHdrMetadataEXT structure is defined as:
// Provided by VK_EXT_hdr_metadata
typedef struct VkHdrMetadataEXT {
VkStructureType sType;
const void* pNext;
VkXYColorEXT displayPrimaryRed;
VkXYColorEXT displayPrimaryGreen;
VkXYColorEXT displayPrimaryBlue;
VkXYColorEXT whitePoint;
float maxLuminance;
float minLuminance;
float maxContentLightLevel;
float maxFrameAverageLightLevel;
} VkHdrMetadataEXT;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
displayPrimaryRedis a VkXYColorEXT structure specifying the reference monitor’s red primary in chromaticity coordinates -
displayPrimaryGreenis a VkXYColorEXT structure specifying the reference monitor’s green primary in chromaticity coordinates -
displayPrimaryBlueis a VkXYColorEXT structure specifying the reference monitor’s blue primary in chromaticity coordinates -
whitePointis a VkXYColorEXT structure specifying the reference monitor’s white-point in chromaticity coordinates -
maxLuminanceis the maximum luminance of the reference monitor in nits -
minLuminanceis the minimum luminance of the reference monitor in nits -
maxContentLightLevelis content’s maximum luminance in nits -
maxFrameAverageLightLevelis the maximum frame average light level in nits
|
Note
The validity and use of this data is outside the scope of Vulkan. |
The VkXYColorEXT structure is defined as:
// Provided by VK_EXT_hdr_metadata
typedef struct VkXYColorEXT {
float x;
float y;
} VkXYColorEXT;-
xis the x chromaticity coordinate. -
yis the y chromaticity coordinate.
Chromaticity coordinates are as specified in CIE 15:2004 “Calculation of chromaticity coordinates” (Section 7.3) and are limited to between 0 and 1 for real colors for the reference monitor.
34.12. Present Barrier
The VK_NV_present_barrier extension allows applications to
synchronize corresponding presentation requests across multiple swapchains
using the present barrier.
A swapchain is said to be using the present barrier if the swapchain is
created by adding a VkSwapchainPresentBarrierCreateInfoNV structure to
the pNext chain of the VkSwapchainCreateInfoKHR structure, and
setting
VkSwapchainPresentBarrierCreateInfoNV::presentBarrierEnable to
true.
A set of corresponding presentation requests is defined as exactly one queued presentation request associated with each swapchain using the present barrier, whether or not that queued request has executed. A given presentation request is added, when created by calling vkQueuePresentKHR and specifying a swapchain using the present barrier, either to the oldest existing set of corresponding requests for which there is no existing member associated with the request’s swapcahin, or to a new set of corresponding requests if no such set exists.
A set of corresponding requests is said to be full when it contains one request from each swapchain using the present barrier. Queued presentation of an image to a swapchain using the present barrier is deferred by the implementation until the set of corresponding requests is full, and the visibility operations associated with all requests in that set, as described by vkQueuePresentKHR, have completed.
Additionally, the set of swapchains using the present barrier can be in the same process, or different processes running under the same operating system. And if the required synchronization hardware is connected and correctly configured, this extension also supports applications to synchronize corresponding presentation requests using the present barrier across distributed systems. However, the configuration mechanism of the required hardware is outside the scope of the Vulkan specification and this extension.
The VkSwapchainPresentBarrierCreateInfoNV structure is defined as:
// Provided by VK_NV_present_barrier
typedef struct VkSwapchainPresentBarrierCreateInfoNV {
VkStructureType sType;
void* pNext;
VkBool32 presentBarrierEnable;
} VkSwapchainPresentBarrierCreateInfoNV;-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
presentBarrierEnableis a boolean value indicating a request for using the present barrier.
If the pNext chain of VkSwapchainCreateInfoKHR does not include
this structure, the default value for presentBarrierEnable is
VK_FALSE, meaning the swapchain does not request to use the present
barrier.
Additionally, when recreating a swapchain that was using the present
barrier, and the pNext chain of VkSwapchainCreateInfoKHR does
not include this structure, it means the swapchain will stop using the
present barrier.